Refrigerant leak detection

Abstract

A refrigerant control system comprising: a charge module configured to determine an amount of refrigerant present within a refrigeration system of a building; a leak module configured to diagnose a presence of a leak in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis of the presence of the leak in the refrigeration system.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Nonprovisional Application No. 16 / 940,843, filed July 28, 2020. The entire disclosure of the above-cited application is incorporated herein by reference. Technical Field

[0003] This disclosure relates to refrigeration systems, and more specifically, to leak detection and isolation devices for refrigeration systems. Background Technology

[0004] This section provides background information related to the contents of this disclosure, which is not necessarily prior art.

[0005] Refrigeration and air conditioning applications are facing 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 need to be increased.

[0006] Several refrigerants have been developed as options with low global warming potential, and they have the ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) classification of A2L, which signifies slightly flammable. UL (Underwriters Laboratories) standard 60335-2-40 and similar standards specify predetermined (M1) levels for A2L refrigerants and indicate that refrigerant charge levels below the predetermined level do not require leak detection and mitigation. Summary of the Invention

[0007] This section provides a general overview of the contents of this disclosure and is not a full disclosure of its entire scope or all its features.

[0008] This disclosure relates to system configurations and control methods for maintaining the level of A2L refrigerant within any isolated section of a building or system, or within a fixed installation within a system, below a predetermined level specified for A2L refrigerant. While this disclosure provides examples of A2L refrigerant, it is applicable to other types of refrigerants as well.

[0009] Residential and commercial heating, ventilation, and air conditioning (HVAC) systems may include isolation valves placed in the refrigerant lines such that, in the event of a leak, one or more isolation valves will automatically close, and the amount of refrigerant maintained within any specific section between the isolation valves within the building will be below a predetermined level (M1). In some applications, leak sensors may be placed around the system so that, as a mitigation measure, the isolation valves will be forced to close in the event of a leak.

[0010] In larger refrigeration systems, such as those in supermarkets, refrigerant charges can be very high, hundreds of pounds or more. By using leak sensors and isolation valves, the isolation valves can shut off the section where a leak is detected in the event of a leak. This minimizes the potential amount of leakage and allows the rest of the system to continue operating. This can be a significant advantage in meeting one or more regulatory requirements and / or reducing the overall leak rate. In residential or commercial building configurations with air conditioning (AC) and / or heat pump systems using A2L refrigerant, where the system charge is higher than the M1 charge level, leak detection, control, and mitigation systems may be required. Once a refrigerant leak is detected, the control module can activate a reversing valve and a series of isolation valves that work in conjunction with the compressor to pump refrigerant and isolate it outside the building.

[0011] In configurations for AC-only systems, the control module closes the isolation valve after each system cycle, isolating most of the refrigerant outside the building, while the refrigerant charge inside the building remains below a predetermined level (M1). This eliminates the need for A2L leak detection and mitigation by preventing the amount of refrigerant inside the building from exceeding the predetermined level (M1).

[0012] In configurations for AC-only systems, various sensors (e.g., temperature, pressure, etc.) can be added to the system. The sensors provide measurements, which the control module can use to determine the charge level within the building and the total charge within the system. The control module can also track any charge losses, which could be an indication of a leak. Adding controls enables more complex control mechanisms. Based on data from additional temperature and pressure sensors, in the event of a refrigerant leak, the control module can execute a pumping sequence that removes a significant portion of the refrigerant from a portion of the system within the building and shuts off valves, thus ensuring that most of the refrigerant remains in a portion of the system outside the building. This may result in the refrigerant level within the building falling below a predetermined level (M1).

[0013] In this feature, the vapor compression system includes: a refrigeration cycle comprising a compressor and a condenser and an indoor component, wherein at least the condenser is located outdoors, and the indoor component includes an expansion valve and an evaporator; a first isolation valve disposed between the evaporator and the compressor in the refrigeration cycle; a second isolation valve disposed between the condenser and the expansion valve in the refrigeration cycle, wherein the first and second isolation valves are operable to close to isolate the indoor component of the refrigeration cycle from the outdoor portion; and a control module configured to control the operation of the first and second isolation valves and to maintain the amount of refrigerant in the indoor component below level M1.

[0014] In this feature, the vapor compression system includes: a refrigeration cycle comprising a compressor and a condenser, and an indoor component, wherein at least the condenser is located outdoors, and the indoor component includes an expansion valve and an evaporator; a first isolation valve disposed between the evaporator and the compressor in the refrigeration cycle; a second isolation valve disposed between the condenser and the expansion valve in the refrigeration cycle, wherein the first and second isolation valves are operable to close to isolate the indoor component from the condenser; and a control module configured to sequentially open and close the first and second isolation valves and to operate the compressor to pump refrigerant from the indoor component of the refrigeration cycle to the outdoor component, wherein the refrigeration cycle has no accumulator.

[0015] In another feature, the control module is configured to perform pumping via a predetermined timing delay of a first isolation valve, wherein the first isolation valve is actuated to close in response to suction pressure or temperature.

[0016] In another feature, the first isolation valve is a check valve.

[0017] In another feature, the sequence of the first isolation valve and the second isolation valve ensures that the refrigerant in the indoor unit does not exceed a predetermined amount during the shutdown period.

[0018] In this feature, the vapor compression system includes: a refrigeration cycle comprising a compressor and a condenser, and an indoor component, wherein at least the condenser is an outdoor component, and the indoor component includes an expansion valve and an evaporator; a first isolation valve disposed between the evaporator and the compressor in the refrigeration cycle; a second isolation valve disposed between the condenser and the expansion valve in the refrigeration cycle, wherein the first and second isolation valves are operable to close to isolate the indoor component from the outdoor component; and a control module configured to control the operation of the compressor to open and close the first and second isolation valves, to perform indoor and outdoor charge calculations based on at least one of pressure and temperature, and to control the operation of the first and second isolation valves based on the indoor and outdoor charge calculations.

[0019] In another feature, the control module is configured to close the first and second isolation valves when the system is not in operation.

[0020] In another feature, the control module is configured to close the first and second isolation valves and stop the compressor when a leak is detected in the charging calculation system.

[0021] In another feature, the control module is configured to shut down the compressor if the compressor suction pressure drops below a predetermined value.

[0022] In another feature, an indoor fan is positioned near the evaporator, and the control module is configured to operate the indoor fan when a leak is detected in the charging calculation system.

[0023] In another feature, in the event of a leak, the control module is configured to operate the indoor fan for a predetermined duration after the compressor is shut off.

[0024] In another feature, the control module is configured to independently open and close the first isolation valve and the second isolation valve.

[0025] In another feature, when a leak is filled in the computing indicator system, the control module is configured to generate at least one of the following: generate a visual indicator, generate an auditory indicator, and transmit the indicator to an external device.

[0026] In the features, the vapor compression system includes: a refrigeration cycle comprising a compressor and a condenser and an indoor component, wherein at least the condenser is an outdoor component, and the indoor component includes an expansion valve and an evaporator; a first pressure sensor and a first temperature sensor disposed upstream of the compressor; a second pressure sensor and a second temperature sensor disposed upstream of the expansion valve; an indoor fan disposed near the evaporator; and a control module configured to control the operation of the compressor and the indoor fan, wherein the control module is configured to calculate the indoor charge and the outdoor charge based on measurements from the first and second pressure sensors and the first and second temperature sensors, and to determine whether there is a refrigerant leak based on the calculated indoor and outdoor charge, wherein the control module is configured to operate the indoor fan when a refrigerant leak is detected.

[0027] In another feature, the control module is configured to operate the indoor fan for a predetermined period of time.

[0028] In another feature, the control module is configured to disable the compressor when the charge calculation indicates a leak.

[0029] In this feature, the refrigeration system includes: a refrigeration cycle having an outdoor component and an indoor component, the outdoor component including at least one compressor and a condenser, and the indoor component including a plurality of expansion valves and a plurality of evaporators; a plurality of refrigerant leak sensors, each refrigerant leak sensor being configured adjacent to a corresponding evaporator among the plurality of evaporators; a plurality of first isolation valves, each first isolation valve being configured upstream of a corresponding evaporator among the plurality of evaporators; and a plurality of second isolation valves, each second isolation valve being configured downstream of a corresponding evaporator among the plurality of evaporators; and a control module configured to receive signals from the plurality of refrigerant leak sensors, and, in the event that a leak is detected by the refrigerant leak sensors, to close a corresponding isolation valve among the plurality of first isolation valves and a corresponding isolation valve among the plurality of second isolation valves associated with one of the plurality of evaporators, thereby isolating one of the plurality of evaporators from the rest of the system.

[0030] In other features, the first isolation valve and the second isolation valve are selected from sealed ball valves, solenoid valves, electronic expansion valves, check valves, needle valves, butterfly valves, gate valves, vertical slide valves, throttle valves, knife valves, pinch valves, plug valves, gate valves and diaphragm valves.

[0031] In another feature, the control module is configured to independently open and close multiple first isolation valves and second isolation valves.

[0032] In another feature, when the refrigerant leak sensor indicates a leak in the system, the control module is configured to generate at least one of visual indication, auditory indication, and communication with an external device.

[0033] In this feature, the refrigeration system includes: a refrigeration cycle having an outdoor component and an indoor component, the outdoor component including at least one compressor and a condenser, and the indoor component including a plurality of electrically operated expansion valves and a plurality of evaporators; a plurality of refrigerant leak sensors, each refrigerant leak sensor being configured to be adjacent to a corresponding evaporator among the plurality of evaporators; a plurality of isolation valves, each isolation valve being configured to be downstream of a corresponding evaporator among the plurality of evaporators; and a control module configured to receive signals from the plurality of refrigerant leak sensors, and, when a refrigerant leak sensor detects a leak, to close a corresponding electrically operated expansion valve among the plurality of electrically operated expansion valves and a corresponding isolation valve among the plurality of isolation valves associated with one of the plurality of evaporators, thereby isolating one of the plurality of evaporators from the rest of the system.

[0034] Among other features, the isolation valves are selected from sealed ball valves, solenoid valves, electronic expansion valves, check valves, needle valves, butterfly valves, gate valves, vertical slide valves, throttle valves, knife valves, pinch valves, plug valves, gate valves, and diaphragm valves.

[0035] In another feature, the control module is configured to independently open and close multiple electrically operated expansion valves and multiple isolation valves.

[0036] In another feature, when the refrigerant leak sensor indicates a leak in the system, the control module is configured to generate at least one of the following: generate a visual indication, generate an audible indication, and transmit the indication to an external device.

[0037] In this feature, the heating, ventilation, and air conditioning (HVAC) system includes: a refrigeration cycle comprising a compressor and condenser disposed outdoors relative to the building, and an expansion valve and evaporator disposed indoors relative to the building; a first isolation valve disposed indoors between the evaporator and the compressor in the refrigeration cycle; a second isolation valve disposed outdoors between the condenser and the expansion valve in the refrigeration cycle; a first temperature sensor disposed between the second isolation valve and the expansion valve, and a second temperature sensor disposed between the expansion valve and the evaporator; and a control module configured to diagnose the presence of leakage through the expansion valve based on measurements from the first and second temperature sensors, and to control the state of the first and second isolation valves and the operation of the compressor.

[0038] In this feature, the HVAC system includes: a refrigeration cycle including a compressor and condenser disposed outdoors relative to the building, and an expansion valve and evaporator disposed indoors relative to the building; a first isolation valve disposed indoors between the evaporator and the compressor in the refrigeration cycle; a second isolation valve disposed outdoors between the condenser and the expansion valve in the refrigeration cycle; a first pressure sensor disposed between the second isolation valve and the expansion valve, and a second pressure sensor disposed between the expansion valve and the evaporator; and a control module configured to diagnose leakage through the expansion valve based on measurements from the first and second pressure sensors, and to control the state of the first and second isolation valves and the operation of the compressor.

[0039] In this feature, the HVAC system includes: a refrigeration cycle comprising a compressor and condenser disposed outdoors relative to the building, and an expansion valve and evaporator disposed indoors relative to the building; a first isolation valve disposed indoors between the evaporator and the compressor in the refrigeration cycle; a second isolation valve disposed outdoors between the evaporator and the compressor in the refrigeration cycle; a third isolation valve disposed indoors between the condenser and the expansion valve in the refrigeration cycle; a fourth isolation valve disposed outdoors between the condenser and the expansion valve in the refrigeration cycle; a first temperature sensor disposed upstream of the first isolation valve; a second temperature sensor disposed between the first isolation valve and the second isolation valve; a third temperature sensor... A temperature sensor is located downstream of the second isolation valve; a fourth temperature sensor is located upstream of the fourth isolation valve; a fifth temperature sensor is located between the fourth and third isolation valves; a sixth temperature sensor is located downstream of the third isolation valve; and a control module is configured to control the status of the first, second, third, and fourth isolation valves and the operation of the compressor, wherein the control module is configured to diagnose leaks when the first, second, third, and fourth isolation valves are closed based on measurements from the first, second, third, fourth, fifth, and sixth temperature sensors.

[0040] In this feature, the vapor compression system includes: a refrigeration cycle comprising a compressor and a condenser, and an indoor component, wherein at least the condenser is an outdoor component, and the indoor component includes an expansion valve and an evaporator; a first isolation valve disposed between the evaporator and the compressor in the refrigeration cycle; and a second isolation valve disposed between the condenser and the expansion valve in the refrigeration cycle, wherein the first and second isolation valves are operable to close to isolate the indoor component of the refrigeration cycle from the outdoor portion; and a control module configured to calculate the refrigerant charge in the isolated indoor region of the refrigeration cycle, and to control the first and second isolation valves and maintain the refrigerant charge in the isolated region below a predetermined charge level.

[0041] In another feature, the control module is configured to calculate the refrigerant charge in the isolation chamber area based on the liquid temperature, suction temperature, and suction pressure.

[0042] In another feature, the control module is configured to calculate the refrigerant charge in the isolation chamber area based on the liquid temperature, suction temperature, and evaporator temperature.

[0043] In another feature, the control module is configured to use the relationship between the specific volume and enthalpy of the refrigerant phase region to calculate the refrigerant charge.

[0044] In another feature, the control module calculates refrigerant charge based on a predetermined ratio between the logarithmic mean temperature difference and enthalpy change between the measured value and the predetermined design value, and a predetermined ratio between the total heat transfer coefficients of liquid, vapor and 2-phase heat transfer.

[0045] In the features, the vapor compression system includes: a refrigeration cycle comprising a compressor and a condenser and an indoor component, wherein at least the condenser is an outdoor component and the indoor component includes an expansion valve and an evaporator; and a control module configured to calculate the indoor refrigerant charge and the outdoor refrigerant charge of the system to determine the total charge of the system based on the indoor and outdoor refrigerant charges, and to diagnose the presence of a leak based on the total charge of the system.

[0046] In another feature, the control module is configured to calculate the indoor refrigerant charge based on the liquid temperature, suction temperature, and suction pressure.

[0047] In another feature, the control module is configured to calculate the indoor refrigerant charge based on the liquid temperature, suction temperature, and evaporation temperature.

[0048] In another feature, the control module is configured to calculate the outdoor refrigerant charge based on liquid temperature, liquid pressure, and suction temperature.

[0049] In another feature, the control module is configured to calculate the outdoor refrigerant charge based on the liquid temperature, suction temperature, and condensation temperature.

[0050] In another feature, the control module is configured to calculate indoor and outdoor refrigerant charges based on the relationship between the specific volume and enthalpy of the refrigerant phase region.

[0051] In one feature, a refrigerant control system includes: a charging module configured to determine the amount of refrigerant present in a building's refrigeration system; a leakage module configured to diagnose a leak in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis of a leak in the refrigeration system.

[0052] In another feature, at least one module includes: an isolation module configured to close a first isolation valve located between a first heat exchanger located outside the building and a second heat exchanger located inside the building in response to a diagnosis of a leak in the refrigeration system; and a compressor module configured to operate the compressor of the refrigeration system for a predetermined period of time in response to a diagnosis of a leak in the refrigeration system.

[0053] In another feature, the isolation module is also configured to close the second isolation valve located between the compressor and the second heat exchanger in the refrigeration system in response to a determination that a predetermined period of time has elapsed.

[0054] In another feature, the first isolation valve and the second isolation valve are located outside the building.

[0055] In another feature, the charging module is configured to determine the amount of refrigerant in the refrigeration system based on at least one of the temperature of the refrigerant in the refrigeration system and the pressure of the refrigerant in the refrigeration system.

[0056] In another feature, the charging module is configured to determine the amount of refrigerant in the refrigeration system based on the volume of the first heat exchanger located outside the building, the volume of the second heat exchanger located inside the building, and the volume of the refrigerant pipeline of the refrigeration system.

[0057] In another feature, the charging module is configured to determine the volume of the first heat exchanger based on at least one temperature and at least one pressure of the refrigerant within the refrigeration system and the volumetric flow rate of the compressor of the refrigeration system.

[0058] In another feature, the charging module is configured to determine the volume of the refrigerant line based on at least one temperature and at least one pressure of the refrigerant within the refrigeration system and the volumetric flow rate of the compressor of the refrigeration system.

[0059] In another feature, the leak module is configured to diagnose leaks in the refrigeration system based on measurements from a leak sensor located at the evaporator of the refrigeration system.

[0060] In another feature, the leak module is configured to diagnose a leak in the refrigeration system when the pressure of the refrigerant in the building, as measured by a pressure sensor within the building, decreases.

[0061] In another feature, at least one module configured to take at least one remedial action includes: an alarm module configured to generate an alarm via a visual indicator in response to a diagnosis of a leak in the refrigeration system.

[0062] In another feature, at least one module configured to take at least one remedial action includes: an alarm module configured to send an alarm to an external device via a network in response to a diagnosis of a leak in the refrigeration system.

[0063] In another feature: the charging module is configured to: determine a first amount of refrigerant present in a first part of the refrigeration system located inside the building; determine a second amount of refrigerant present in a second part of the refrigeration system located outside the building; determine the amount of refrigerant in the refrigeration system based on the first amount of refrigerant in the first part and the second amount of refrigerant in the second part; and the leakage module is configured to diagnose a leak in the refrigeration system based on at least one of the following: the first amount of refrigerant, the second amount of refrigerant, and the amount of refrigerant.

[0064] In one feature, a refrigerant control method includes: determining the amount of refrigerant present in a building's refrigeration system; diagnosing a leak in the refrigeration system based on the amount of refrigerant; and performing at least one remedial action in response to the diagnosis of a leak in the refrigeration system.

[0065] In another feature, at least one remedy includes: closing a first isolation valve located outside the building and a second heat exchanger located inside the building; and operating the compressor of the refrigeration system for a predetermined period of time.

[0066] In another feature, determining the amount of refrigerant includes determining the amount of refrigerant in the refrigeration system based on at least one of the temperature of the refrigerant in the refrigeration system and the pressure of the refrigerant in the refrigeration system.

[0067] In another feature, the diagnosis includes diagnosing the presence of a leak in the refrigeration system based on measurements from a leak sensor located at the evaporator of the refrigeration system.

[0068] In another feature, the diagnosis includes diagnosing a leak in the refrigeration system when the pressure of the refrigerant inside the building, as measured by a pressure sensor within the building, decreases.

[0069] In an additional feature, at least one remedy includes at least one of the following: generating an alarm via a visual indicator; and sending an alarm to an external device via a network.

[0070] In another feature: the determination includes: determining a first amount of refrigerant present in a first portion of the refrigeration system located within a building; determining a second amount of refrigerant present in a second portion of the refrigeration system located outside the building; determining the amount of refrigerant in the refrigeration system based on the first amount of refrigerant in the first portion and the second amount of refrigerant in the second portion; and the diagnosis includes diagnosing a leak in the refrigeration system based on at least one of the following: the first amount of refrigerant, the second amount of refrigerant, and the amount of refrigerant.

[0071] Further areas of application will become apparent from the descriptions provided herein. The descriptions and specific examples in this overview are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0072] The accompanying drawings described herein are for illustrative purposes only and do not represent all possible implementations, nor are they intended to limit the scope of this disclosure.

[0073] Figures 1A to 1C A schematic diagram of a residential split-type air conditioning system;

[0074] Figure 2 This is a schematic diagram of the rack cooling system;

[0075] Figure 3 A schematic diagram of a micro turbocharger cooling system;

[0076] Figure 4 A flowchart illustrating an example method for controlling an indoor fan in an HVAC system;

[0077] Figures 5A to 5B A flowchart illustrating an example method for controlling isolation valves and compressors in a refrigeration or HVAC system;

[0078] Figure 6 A functional block diagram of an example air conditioning system including an isolation valve, a pressure sensor, and a temperature sensor;

[0079] Figure 7 A functional block diagram of an example air conditioning system including an isolation valve, a pressure sensor, and a temperature sensor;

[0080] Figure 8 A functional block diagram of an example air conditioning system including an isolation valve and a leak sensor;

[0081] Figure 9 A flowchart illustrating an example method for detecting refrigerant leaks;

[0082] Figure 10 and Figure 11 Here is a functional block diagram of an example refrigeration system including an isolation valve;

[0083] Figure 12 A functional block diagram of an example refrigeration system that includes pressure and temperature sensors;

[0084] Figure 13 A functional block diagram of an example refrigeration system that includes a temperature or pressure sensor;

[0085] Figure 14 A functional block diagram of an example refrigeration system including redundant isolation valves and temperature or pressure sensors; and

[0086] Figure 15 This is a functional block diagram of an example control system that includes control modules.

[0087] Throughout the various views of the accompanying drawings, corresponding reference numerals indicate the respective components. Detailed Implementation

[0088] Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments are provided so that this disclosure will be thorough and will more fully convey the scope to those skilled in the art. Numerous specific details, such as examples of particular components, apparatuses, and methods, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that specific details are not required, example embodiments may be implemented in many different forms, and neither the specific details nor the example embodiments should be construed as limiting the scope of this disclosure. In some example embodiments, well-known processes, well-known apparatus structures, and well-known techniques have not been described in detail.

[0089] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” may also be intended to include the plural forms. The terms “comprises,” “comprising,” “including,” and “having” are inclusive and therefore specify the presence of the said features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The methods, steps, processes, and operations described herein should not be construed as requiring them to be performed in the particular order discussed or shown, unless specifically identified as such. It should also be understood that additional or alternative steps may be employed.

[0090] When an element or layer is referred to as “on another element or layer,” “joined to,” “connected to,” or “coupled to” another element or layer, the element or layer may be directly on, joined to, connected to, or coupled to the other element or layer, or there may be intermediate elements or layers present. In contrast, when an element is referred to as “directly on another element or layer,” “directly joined to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intermediate elements or layers present. Other terms used to describe relationships between elements (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.) should be interpreted in the same manner. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0091] Although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or portion from another. For example, the terms “first,” “second,” and other numerical terms used herein do not imply a sequence or order unless explicitly indicated by the context. Therefore, the first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0092] For ease of description, spatial relative terms such as “inner,” “outer,” “below,” “below,” “lower,” “above,” “upper,” etc., are used herein to describe the relationship between one element or feature as illustrated in the accompanying drawings and another element or feature (or other elements or features). Spatial relative terms may be intended to cover different orientations of the device in use or operation other than those depicted in the accompanying drawings. For example, if the device in the accompanying drawings is flipped, an element described as “below other elements or features” or “below other elements or features” will be oriented “above other elements or features.” Thus, the example term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein may be interpreted accordingly.

[0093] Reference Figures 1A to 1C The diagram shows a split-type air conditioning (AC) system 10, which includes a compressor 12 and a condenser 14 located outside a building 15 (i.e., outdoors) that uses the AC system 10 for cooling. The AC system 10 also includes an expansion valve 16 and an evaporator 18 located inside the building 15 that uses the AC system 10 for cooling (i.e., indoors).

[0094] The first isolation valve 20 is located outside the building 15 and between the evaporator 18 and the compressor 12. The second isolation valve 22 is located outside the building 15 and between the condenser 14 and the expansion valve 16. Refrigerant lines are connected between the components of the AC system 10. For example, a refrigerant line is connected between the compressor 12 and the condenser 14, between the condenser 14 and the second isolation valve 22, between the second isolation valve 22 and the expansion valve 16, between the expansion valve 16 and the evaporator 18, between the evaporator 18 and the first isolation valve 20, and between the first isolation valve 20 and the compressor 12.

[0095] exist Figure 1A The image shows an AC system 10 in the "off" state, with the compressor 12 off and the first isolation valve 20... c Second isolation valve 22 c closure. Figure 1B The AC system 10 is shown in normal operating mode, with the compressor "on" and the first isolation valve 20... o Second isolation valve 22 o Open. During shutdown, such as... Figure 1C As shown, the control module (discussed further below) can close the second isolation valve 22. c Maintain the first isolation valve 20 o The compressor 12 is turned on and kept running for a predetermined period. This draws refrigerant from the indoor section of the AC system 10 and traps it in the outdoor section of the air conditioning system 10. After the predetermined period has elapsed, the control module can close the first isolation valve 20. o And shut off compressor 12, such as Figure 1A As shown. This isolates the indoor section I of the AC system 10 from the outdoor section O. The act of pumping refrigerant from the indoor section I to the outdoor section O reduces the amount (e.g., mass or weight) of refrigerant in the indoor section I to less than a predetermined amount, preferably below the minimum level of the M1 charge level of the A2L refrigerant.

[0096] Isolation valves 20 and 22 can be positive seals and are controlled by a control module. The control module also controls operation (e.g., opening or closing) and can control the speed of compressor 12. The control module selectively controls isolation valves 20 and 22 according to operating conditions and requirements to selectively divide the AC system 10, including piping (refrigerant lines) and system components, into zones. In various implementations, isolation valve 20 can be integrated with compressor 12, for example, as a discharge check valve or a suction check valve. Isolation valves 20 and 22 can be sealed ball valves, solenoid valves, electronic expansion valves, check valves, needle valves, butterfly valves, gate valves, vertical slide valves, throttle valves, knife valves, pinch valves, plug valves, gate valves, diaphragm valves, or other suitable types of actuated valves.

[0097] During pump-out operation, the refrigerant moves to the isolated outdoor area of ​​the system at the end of the compressor operating cycle. This reduces the amount of refrigerant that may leak into building 15 when the compressor is not operating.

[0098] The control module can communicate wirelessly or wiredly with the compressor 12, one or more fans, isolation valves 20, 22, and various sensors, directly or indirectly. The control module may include one or more modules and can be implemented as part of a control board, furnace board, thermostat, air handling unit board, contactor, or other form of control or diagnostic system. The control module may include a power regulation circuitry to supply power to various components using 24 volts (V) alternating current (AC), 120V to 240V AC, 5V direct current (DC), etc. The control module may include bidirectional communication, which can be wired, wireless, or a combination of both, enabling system debugging, programming, updates, monitoring, parameter value / status transmission, etc. The AC system can be more generally referred to as a refrigeration system.

[0099] Reference Figure 2 The diagram illustrates a rack-mounted refrigeration system 30 for a building 35 (e.g., a commercial building, such as a supermarket). The rack-mounted refrigeration system 30 includes multiple compressors 32A to 32C and a condenser 34 disposed in an outdoor or ventilated indoor room of the building 35. Multiple electronic expansion valves or thermal expansion valves 36A to 36D (hereinafter referred to as "expansion valves 36A to 36D") and multiple evaporators 38A to 38D are located within the building 35 (i.e., inside the building 35 or in the indoor side I).

[0100] The first isolation valve 40 is located on the outdoor side O (i.e., outdoors) of the building 35 and between the condenser 34 and the plurality of evaporators 38A to 38D. The plurality of second isolation valves 42A to 42D can be located between the condenser 34 and the expansion valves 36A to 36D within the indoor section I of the refrigeration system 30. If electronic expansion valves 36A to 36D are used and can be properly sealed, the plurality of second isolation valves 42A to 42D can be omitted, and the expansion valves 36A to 36D can be used as isolation valves 42A to 42D.

[0101] Multiple third isolation valves 44A to 44D are respectively disposed between multiple evaporators 38A to 38D and compressors 32A to 32C, for example, within indoor section I. A fourth isolation valve 46 may be disposed outside building 35 and upstream of the multiple compressors 32A to 32C. Although an example of three compressors is provided, more or fewer compressors may be used. A fifth isolation valve 47 may be disposed between multiple compressors 32 and condenser 34. Although an example of condenser 34 is provided, multiple condensers may be connected in parallel.

[0102] Multiple leak sensors 48A to 48D can be placed near each of the multiple evaporators 38A to 38D, for example, at the midpoint of each of the evaporators 38A to 38D. The evaporators 38A to 38D can be positioned at the lowest point of the refrigeration system 30 (i.e., below the other components of the refrigeration system 30). Because A2L refrigerant may be heavier than air, placing the leak sensors 48A to 48D near the evaporators 38A to 38D increases the likelihood of detecting a leak in the indoor section I.

[0103] Leak sensors 48A to 48D can be, for example, infrared leak sensors, optical leak sensors, chemical leak sensors, thermally conductive leak sensors, acoustic leak sensors, ultrasonic leak sensors, or other suitable types of leak sensors. Control module 49 is configured to communicate with isolation valves, compressors 32A to 32C, and leak sensors 48A to 48D. If a leak is detected at one of the evaporators 38A to 38D, control module 49 can close the associated isolation valves 42A to 42D, 44A to 44D, or electronic expansion valves 36A to 36D of that evaporator 38A to 38D. This isolates the leaking evaporator 38A to 38D, allowing the remaining evaporators 38A to 38D of the refrigeration system to continue operating without interruption, while preventing refrigerant from escaping from the refrigeration system.

[0104] The control module 49 can close the additional isolation valves 40 and 46 to isolate the indoor cooling section from the outdoor cooling section, for example, when the cooling system is off or during maintenance.

[0105] Multiple compressors 32A to 32C may be equipped with oil separators, and liquid receivers may be located downstream of condenser 34. Each of evaporators 38A to 38D may be associated with a predetermined low-temperature (e.g., for frozen foods) or predetermined medium-temperature (e.g., for refrigerated foods) compartment.

[0106] Reference Figure 3 The diagram illustrates a refrigeration system 60 (e.g., a micro-pressurized refrigeration system) including a (e.g., medium-temperature) condensing unit 61, which comprises multiple outdoor compressors 62A to 62B and a condenser 64 disposed outside a building 65 (e.g., a supermarket or other type of commercial building). Multiple expansion valves 66A to 66B and multiple evaporators 68A to 68B are disposed within the building 65 (i.e., indoors).

[0107] An additional compressor unit 62C may be included within building 65 and connected to evaporator 68B. Evaporator 68B may be associated with a low-temperature (frozen food) refrigerator compartment, while evaporator 68A may be associated with a higher (e.g., medium) temperature (e.g., refrigerated food) refrigerator compartment.

[0108] A first isolation valve 70 is disposed between the condenser 64 and a plurality of evaporators 68A to 68B (e.g., in the outdoor side O of building 65). A plurality of second isolation valves 72A to 72B may be disposed between the condenser 64 and expansion valves 66A to 66B, for example, in the indoor section I of the refrigeration system 60. If the electronic expansion valves 66A to 66B are implemented and configured to be sealed, the plurality of second isolation valves 72A to 72B may be omitted, and the electronic expansion valves 66A to 66B may serve as isolation valves.

[0109] Multiple third isolation valves 74A to 74B are respectively located downstream of multiple evaporators 78A to 78B and between evaporators 78A to 78B and compressors 62A to 62B. A fourth isolation valve 76 can be located upstream of the multiple compressors 62A to 62B, for example, inside or outside building 65. A fifth isolation valve 77 can be located between cryogenic compressor 62C and compressors 62A to 62B.

[0110] Multiple leak sensors 78A to 78B can be respectively installed near multiple evaporators 68A to 68B. Evaporators 68A to 68B can be located at the lowest point of the refrigeration system 60. Because A2L refrigerant may be heavier than air, placing leak sensors 78A to 78B near evaporators 68A to 68B can increase the likelihood of detecting leaked A2L refrigerant in the indoor environment I.

[0111] Leak sensors 78A to 78B can be infrared leak sensors, optical leak sensors, chemical leak sensors, thermal leak sensors, acoustic leak sensors, ultrasonic leak sensors, or other suitable types of leak sensors. If a leak is detected at one of the multiple evaporators 68A to 68B, the control module can close the associated isolation valves 72A to 72B, 74A to 74B, or electronic expansion valves 66A to 66B to isolate the evaporator 68A to 68B identified as leaking. This allows the remaining evaporators to continue operating without interruption.

[0112] Multiple outdoor compressors 62A to 62B may include an oil separator, and a liquid receiver may be included downstream of condenser 64. Evaporator 68A may be associated with (e.g., a medium-temperature) refrigerator compartment. Evaporator 68B may be associated with (e.g., a low-temperature) refrigerator compartment.

[0113] Control module 90 communicates with isolation valves, compressors, and leak sensors. Control module 90 can control isolation valves 70 and 76, for example, to isolate the indoor section I of refrigeration system 60 from the outdoor section O. Because isolation valve 77 is downstream of compressor 62C, isolation valve 74B can be omitted.

[0114] Control module 90 can control isolation valves 76 and 77 to minimize leakage potential based on the amount of refrigerant captured in each of the indoor and outdoor sections. An additional outdoor leak sensor 84 may be included, for example, to detect refrigerant leaks from condenser unit 61.

[0115] Figures 5A to 5B This is a flowchart depicting an example method for controlling the operation of the isolation valve and compressor. The controls discussed in this document can be performed by a control module or one or more sub-modules of a control module.

[0116] At S100, control begins and continues to S101, where control determines whether a leak has been detected. As discussed herein, the control module can detect a leak based on inputs from one or more leak sensors, pressure sensors, and / or temperature sensors. For example, the control module can calculate the amount of refrigerant in the system and determine that a leak exists when the amount of refrigerant has decreased by at least a predetermined amount. Other methods for determining the presence of a leak are discussed herein.

[0117] If no leak is detected at S101, control continues to S102, where the control module resets the pumping timer. The algorithm proceeds to S103, where the control module shuts off the mitigation device. For example, the control module can shut off indoor fans / blowers within the building, such as blowers that blow air across the evaporator. While an example of a fan / blower is provided, one or more other devices configured to mitigate leaks may be additionally or alternatively shut off. If a leak is detected at S101, control transfers to S110, which will be discussed further below.

[0118] At S104, the control module determines whether a call for compressor operation has been received, such as a call from the building's thermostat. If S104 is true, control proceeds to S105. If S104 is false, control transfers to S123, which will be discussed further below.

[0119] At S105, the control module determines whether the compressor is on. If the compressor is on at S105, control returns to S100. If the compressor is off at S104, control continues to S106. At S106, the control module opens one, more than one, or all isolation valves. At S107, the control module determines whether a predetermined compressor power delay period has elapsed since the compressor was last turned off. The control module can determine that the predetermined compressor power delay period has elapsed when the compressor power delay counter is greater than a predetermined value (corresponding to the predetermined compressor power delay period). Although an example of a counter is provided, a timer can be used, and the timer's period can be compared with the predetermined compressor power delay period. If the predetermined compressor power delay has not elapsed at S107, the control module increments the compressor power delay counter (e.g., by 1) at S108, and control returns to S101. If the predetermined compressor power delay has elapsed at S107, the control module turns the compressor on at S109, and control returns to S100.

[0120] As discussed above, if a leak is detected in S101, control continues to S110. In S110, the control module resets the compressor power delay counter (e.g., resets it to zero). While an example of incrementing the counter and resetting it to zero is provided, the control module can alternatively decrement the counter (e.g., decrement by 1), reset the counter to a predetermined value, and compare the counter value to zero. In S111, the control module activates a mitigation device. For example, the control module can activate a fan / blower within the building. Control continues to S112 ( Figure 5B ).

[0121] At S112, the control module generates one or more indicators indicating the presence of leakage. For example, the control module may activate visual indicators (e.g., one or more lights or another type of light-emitting device), display messages on a display, etc. The display may be, for example, a display of the control module or another device (e.g., a thermostat). Additionally or alternatively, the control module may output audible indicators via one or more speakers.

[0122] At S113, the control module determines whether to pump the refrigeration system. The predetermined pumping requirement (e.g., a predetermined pumping period) can be, for example, a setting based on a predetermined volume of the refrigeration system within the building, and is set at installation time and is greater than zero. Alternatively, the predetermined pumping requirement can be determined by the control module, for example, based on indoor charge calculations, as discussed herein. If it is determined at S113 that pumping is not required, control proceeds to S114, where the control module closes the isolation valve. The control module shuts off the compressor at S115, and control returns to S100.

[0123] If the control module determines at S113 that the refrigeration system is being pumped, control proceeds to S116. At S116, the control module determines whether a predetermined pumping period has elapsed since the decision to pump the refrigeration system was made. The control module can determine that the predetermined pumping period has elapsed if the pumping timer is longer than the predetermined pumping period. Although an example of a timer is provided, a counter can be used, and the counter value can be compared with a predetermined value corresponding to the predetermined pumping period. If the predetermined compressor pumping period has not yet elapsed at S116, control proceeds to S117. If the predetermined pumping period has elapsed at S116, control transfers to S121, which will be discussed further below.

[0124] At S117, the control module opens (or remains open) one or more isolation valves implemented in the suction line (e.g., Figures 1A to 1C 20 in the middle, Figure 2 (e.g., 44A to 44C and / or 46, etc.). The isolation valve implemented in the suction line is located between the output of one or more condensers and the input of one or more compressors. At S118, the control module closes (or remains closed) one or more isolation valves implemented in the liquid line (e.g., Figures 1A to 1C 22. Figure 2 (e.g., 42A to 42D and / or 40, etc.). An isolation valve implemented in the liquid line is located between the output of one or more compressors and the input of one or more evaporators. At S119, the control module turns on the compressor. The compressor then draws refrigerant from the indoor section of the refrigeration system and traps the refrigerant in the outdoor section of the refrigeration system, outside the building. At S120, the control module increments the pumping timer, and control returns to S116.

[0125] At S121, when the predetermined pumping period has elapsed, the control module closes the isolation valve (e.g., an isolation valve implemented in the suction line). At S122, the control module shuts off the compressor. Control returns to S100.

[0126] Returning to S104, if the control module determines that no call for compressor operation has been received, control continues to S123. At S123, the control module determines whether the compressor is on. If S123 is true, control continues to S124. At S124, the control module closes or keeps closed (e.g., all) the isolation valves. At S125, the control module shuts off or keeps the compressor off. At S126, the control module resets the compressor delay counter (e.g., resets it to zero), and control returns to S100.

[0127] Regarding pumping operations, during compressor non-operation periods, refrigerant levels within the potential occupied space (indoors, within the building) are minimized by using compressor pumping and by closing the liquid-side isolation valve before compressor shutdown and the vapor line isolation valve when compressor shutdown. The decision-making process may include assessing early leak indicators to prevent larger leaks or evaluating operating frequency to indicate the likelihood of long shutdown periods.

[0128] Reference Figure 6 A functional block diagram of an example refrigeration system 10A (e.g., an air conditioning system) is provided. Figure 6 It includes isolation valves as well as pressure and temperature sensors.

[0129] A system 10A is shown, comprising a compressor 12 and a condenser 14 located outside (i.e., outdoors) of building 15. An expansion valve 16 and an evaporator 18 are located inside (i.e., indoors) of building 15.

[0130] The first isolation valve 20 is located outside, for example, building 15, and is located between the evaporator 18 and the compressor 12 (in the suction line). The second isolation valve 22 is located outside, for example, building 15, and is located between the condenser 14 and the expansion valve 16 (in the liquid line).

[0131] A fan or blower 100 (relief device) is positioned adjacent to the evaporator 18 and is controlled by a first control module 102. A second control module 104 calculates the indoor and outdoor refrigerant charge based on measurements from a first temperature sensor 106 and a first pressure sensor 108 located between the evaporator 18 and the compressor 12, and from a second temperature sensor 110 and a second pressure sensor 112 located between the condenser 14 and the expansion valve 16. The indoor and outdoor refrigerant charge can be calculated when the HVAC system is on, and more specifically, when the compressor 12 is on. The indoor and outdoor refrigerant charge are the amounts (e.g., mass or weight) of refrigerant within the indoor and outdoor sections of the refrigeration system, respectively. The second control module 104 can calculate the indoor charge, for example, using one or more equations or lookup tables that correlate measurements from the temperature and pressure sensors with the indoor charge. The second control module 104 can calculate the outdoor charge, for example, using one or more equations or lookup tables that correlate measurements from the temperature and pressure sensors with the outdoor charge.

[0132] The second control module 104 can determine the total (or overall) refrigerant charge based on the indoor and outdoor refrigerant charge amounts. The second control module 104 can calculate the total charge amount, for example, using one or more equations or lookup tables that relate the indoor and outdoor charge amounts to the total charge amount. For example, the second control module 104 can set the total charge amount based on or equal to the indoor charge amount plus the outdoor charge amount.

[0133] If the total charge decreases by at least a predetermined amount from the refrigerant amount (e.g., the initial amount), the second control module 104 can determine that a leak exists. When the total charge does not decrease by at least a predetermined amount, the second control module 104 can determine that no leak exists. The predetermined amount can be calibrated and can be greater than zero.

[0134] If a leak is detected, the second control module 104 executes a pumping procedure. The second control module 104 closes the second isolation valve 22, opens the first isolation valve 20, and activates the compressor 12 to pump refrigerant from the indoor side I to the outdoor side O of the system 10. The second control module 104 then closes the first isolation valve 20 and shuts off the compressor to isolate the outdoor portion O of the system from the indoor portion I, for example, after a predetermined pumping period has elapsed. When a leak is detected, the second control module 104 prompts the first control module 102 to activate the fan 100. The second control module 104 may also prompt the first control module 102 or itself to activate one or more other mitigation devices when a leak is detected. This may help disperse or reduce any leaked refrigerant.

[0135] The second control module 104 can determine whether a leak exists, for example, by detecting a pressure drop in at least one of the outdoor and indoor sections of the refrigeration system. When the isolation valves 20, 22, the compressor 12, or the expansion device 16 is used to control the refrigerant charge in the indoor section within the potential occupied space, the control module 104 can activate the fan 100 to dilute the refrigerant leak upon detection of a leak.

[0136] Reference Figure 4 A flowchart is provided depicting an example method of controlling a fan (e.g., fan 100) to blow air across one or more evaporators within a building. Indoor fan 100 (e.g., as...) Figure 6 (As shown) This could be a fan throughout the house, such as a stove fan, or it could be a relief fan, such as a bathroom fan, fume hood fan, etc. Control begins at S1. At S2, the control module determines whether the associated cooling system (its compressor) has been turned on within the most recent predetermined period, such as the most recent 24 hours. If the cooling system has been turned on (operated) within the past predetermined period, control continues to S3. If not, control transfers to S6, which will be discussed further below.

[0137] At S3, the control module activates the refrigeration system (e.g., opens the isolation valve and activates the compressor) to regulate the temperature inside the building toward the setpoint temperature. The setpoint temperature can be selected via a thermostat within the building. At S4, the control module determines whether the temperature is at the setpoint temperature. If S4 is true, at S5 the control module shuts off the refrigeration system (e.g., shuts off the compressor and closes the isolation valve), and control returns to S1. If S4 is false, control returns to S3 and the refrigeration system continues to operate.

[0138] At S6 (when the refrigeration system has not been running during the most recent predetermined period), the control module turns on the indoor fan for a predetermined period, such as 3 minutes or other suitable predetermined period. At S7, the control module turns on the refrigeration system (e.g., opens the isolation valve and turns on the compressor) for a predetermined period (e.g., 3 minutes).

[0139] At S8, the control module determines the indoor and outdoor refrigerant charge levels. The control module can use temperature and / or pressure sensors to determine the indoor and outdoor refrigerant charge levels based on temperature and / or pressure (e.g., as shown in the image). Figure 6 , Figure 7 and Figure 12 (As discussed herein). This may include a control module determining (e.g., in real time) the density and volume of liquid, vapor, and two-phase refrigerant in the heat exchangers (evaporator and condenser) to calculate (e.g., in real time) the amount of refrigerant in the indoor and outdoor sections using a predetermined volume of the refrigeration system and measured temperatures and pressures, as further discussed herein.

[0140] At S9, the control module determines whether a leak exists in the refrigeration system based on the indoor and outdoor refrigerant charges relative to a predetermined (e.g., previously stored) charge amount. For example, the control module can determine that a leak exists when the indoor refrigerant charge is less than a predetermined indoor charge and the outdoor refrigerant charge is less than a predetermined outdoor charge. If no leak is detected at S9, control can proceed to S4. If a leak is detected at S9, control can continue to S10, where the control module shuts off the compressor. Control continues to S11, where the control module keeps the indoor fan on, for example, to disperse any leaked refrigerant within the building. At S12, the control module resets the compressor power delay counter (e.g., resets it to zero), and control returns to S1.

[0141] The control module can calculate indoor and outdoor charges based on at least one of the following physical and performance characteristics: evaporator and condenser volumes, logarithmic mean temperature difference between the evaporator and condenser during design, air-side temperature separation, and refrigerant enthalpy changes across the evaporator and / or condenser. The ratio of the overall heat transfer coefficients between the two phases of the evaporator and condenser, and between vapor and liquid, is provided by the system's physical design or observed during installation and initial operation. These characteristics can be inputs to equations and / or lookup tables used to determine indoor and outdoor charges, or are considered during the calibration of these equations and / or lookup tables. When the refrigeration system is turned on, the control module can calculate indoor and outdoor charges. Measured values ​​can include at least one of the following sensed by the refrigeration system's temperature and pressure sensors: liquid line temperature, suction line temperature, outdoor ambient temperature, evaporator temperature, suction pressure, condenser temperature, liquid pressure, condenser pressure, and discharge pressure.

[0142] The control module can determine the indoor charge of the refrigeration system, for example, based on evaporator charge and liquid line charge calculations. The control module can determine the total indoor volume and liquid line volume, for example, by performing a pumping operation, as described above. The calculation of the indoor charge allows the control module to actively control the indoor charge amount and maintain it below a predetermined amount (M1).

[0143] Indoor charge calculations allow for refrigerant charge balance that optimizes system efficiency in response to system capacity. This may additionally include a control module that controls compressor capacity. Total system charge calculations enable the detection and quantification of refrigerant leaks, allowing for alarm activation, isolation of indoor spaces, and leak mitigation. Total system charge calculations also enable the calculation of total refrigerant emissions.

[0144] The charge calculation can be based on various data, including fixed data such as condenser unit manufacturer data, and can be performed as follows:

[0145] V 排量 ● Compressor displacement (e.g., cubic inches per minute);

[0146] V 冷凝单元 ● The internal volume of the condensation unit between isolation valves based on the geometry of the original equipment manufacturer (OEM) model;

[0147] ΔT 对数平均蒸发器2Φ设计 / (h 蒸发器饱和 -h 蒸发器入口 ) 设计 ●The standard ratio of the logarithmic mean temperature difference and enthalpy change of the two-phase section of the evaporator based on the design;

[0148] ΔT 对数平均蒸发器蒸汽设计 / (h 蒸发器出口饱和 -h 蒸发器饱和 ) 设计● The standard ratio of the logarithmic mean temperature difference and enthalpy change of the steam section of the evaporator based on the design; and

[0149] U 比率 =U 蒸发器2Φ / U 蒸发器蒸汽 ●The standard value of the ratio of the total heat transfer coefficient of the two-phase part to the total heat transfer coefficient of the steam part.

[0150] The filling calculation can also be based on the following variable measurement data:

[0151] T 吸入 ● The refrigerant temperature between the steam service valve and the steam isolation valve (or between the steam service valve and the evaporator, if there is only one valve in the line);

[0152] T 液体 ● The refrigerant temperature between the condenser and the liquid isolation valve (or the liquid service valve if there is no isolation valve);

[0153] P 吸入 ● The refrigerant pressure between the steam service valve and the steam isolation valve (or between the steam service valve and the evaporator, if there is only one valve in the line); and

[0154] P 液体 ● The refrigerant pressure between the condenser and the liquid isolation valve (or the liquid service valve if there is no isolation valve).

[0155] The filling calculation data may include a first subset of data, including:

[0156] V 室内 ● The internal volume between the liquid isolation valve and the compressor—including the evaporator, liquid lines, and suction lines—can be calculated by the rate of pressure drop during pumping (or input, if installed without isolation).

[0157] T 排放 ● The refrigerant discharge temperature, for example, is estimated based on refrigerant characteristic data using measured suction conditions, measured liquid pressure, and a predetermined isentropic efficiency of the compression process (e.g., in the range of 60% to 75%).

[0158] T 液体 ,v 液体 ,h 液体 ●The temperature, specific volume, and enthalpy of the liquid refrigerant leaving the condenser unit are estimated, for example, based on regression models of refrigerant characteristic data using liquid temperatures;

[0159] T 蒸发器入口 ,v 蒸发器入口 ,h 蒸发器入口● The temperature, specific volume, and enthalpy of the refrigerant entering the evaporator are estimated, for example, based on regression models using refrigerant characteristic data with liquid temperature and suction pressure.

[0160] T 蒸发器饱和 ,v 蒸发器饱和 ,h 蒸发器饱和 ● The temperature, specific volume, and enthalpy of the saturated vapor refrigerant in the evaporator, estimated, for example, based on regression models using refrigerant characteristic data at suction pressure; and

[0161] T 蒸发器出口 ,v 蒸发器出口 ,h 蒸发器出口 ,ρ 蒸发器出口 ● The temperature, specific volume, enthalpy, and density of the refrigerant leaving the evaporator are estimated, for example, based on regression models using refrigerant characteristic data at suction temperature and pressure.

[0162] The filling calculation data may include a second subset of data, including:

[0163] v 排放 ,h 排放 ●The specific volume and enthalpy of the refrigerant vapor entering the condenser unit, for example, estimated using a regression model with discharge temperature and liquid pressure;

[0164] T 冷凝器饱和蒸汽 ,v 冷凝器饱和蒸汽 ,h 冷凝器饱和蒸汽 ● The temperature, specific volume, and enthalpy of the saturated vapor refrigerant in the condenser, for example, estimated using a regression model employing liquid pressure;

[0165] T 冷凝器饱和液体 ,v 冷凝器饱和液体 ,h 冷凝器饱和液体 ● The temperature, specific volume, and enthalpy of the saturated vapor refrigerant in the condenser, estimated, for example, using liquid pressure based on a regression model;

[0166] U 蒸发器蒸汽 ●The overall heat transfer coefficient of the evaporator is only for the steam portion, for example, only used in comparison with the two-phase portion;

[0167] U 蒸发器2Φ ●The overall heat transfer coefficient of the two-phase section of the evaporator, for example, used only as a ratio to the steam-only section;

[0168] V 液体 ●The internal volume of the liquid line between the isolation valve and the expansion valve; and

[0169] V 蒸发器 ●The internal volume of the evaporator and suction line.

[0170] Pumping commissioning calculations involve the control module calculating the total volume of the indoor system and the volume of the liquid piping based on, for example, the total amount of refrigerant removed during pumping and the rate of change of pressure and density during pumping after the removal of liquid refrigerant. The control module can estimate the total volume using the vapor pumping rate based on pressure and density changes. This can be described by the following equation:

[0171] Total pump outlet charge mass = Σ(ρ 蒸发器出口 ·V 排量 ·Δt 测量 During the entire duration of pumping;

[0172] V 室内 =Σ[(V 排量 ·ρ 蒸发器出口 ·Δt 测量 ) / (ρ 蒸发器出口先前测量 -ρ 蒸发器出口 [); and within a time period after all fluid has been removed, as observed by (e.g., abrupt) changes in suction pressure; and

[0173] Total pump outlet charge mass = V 液体 / v 液体 +2%A 2Φ ·V 蒸发器 / (v 蒸发器入口 +v 蒸发器饱和 )+2·%A 蒸汽 ·V 蒸发器 (v 蒸发器饱和 +v 蒸发器出口 )

[0174] Before pumping out, the data from the end of the refrigeration system's operating cycle is used to balance the above three equations. This balance can then be used to fill the pumping out calculations from the first and second equations into the third combined equation. Using these three equations, the control module can solve for V. 液体 and V 蒸发器 Without an actuated isolation valve, the installer can estimate and store V. 液体 and V 蒸发器 .

[0175] The operational calculations for indoor filling can use the standard equations for isolating steam heat transfer, such as the following:

[0176] Q 蒸发器蒸汽 =m 蒸发器出口 ·(h 蒸发器出口 -h 蒸发器饱和 );as well as

[0177] Q 蒸发器2Φ =m 蒸发器出口 ·(h 蒸发器饱和 -h 蒸发器入口 ).

[0178] The equation for the compressor mass flow rate is as follows:

[0179] m 蒸发器出口 =V 排量 ·ρ 蒸发器出口 .

[0180] This disclosure enables the calculation of the percentage (%A) of evaporator heat transfer area used by the control module for two-phase heat transfer and superheated steam, using design condition data from the OEM. The above formula can be based on thermodynamic calculations, which assume that some ratios will be consistent between routine operation and OEM design conditions.

[0181] Heat transfer by region can be calculated as follows:

[0182] Q 蒸发器蒸汽 =U 蒸发器蒸汽 %A 蒸汽 ·A 总 ·ΔT 对数平均蒸汽 ;

[0183] Q 蒸发器2Φ =U 蒸发器2Φ %A 蒸发器2Φ ·A 总 ·ΔT 对数平均蒸发器2Φ ;

[0184] The area percentages of steam and both phases can be calculated as follows:

[0185] %A 蒸汽 =m 蒸发器出口 ·(h 蒸发器出口 -h 蒸发器饱和 ) / (U 蒸发器蒸汽 ·A 总 ·ΔT 对数平均蒸汽 );

[0186] %A 蒸发器2Φ =m 蒸发器出口 ·(h 蒸发器饱和 -h 蒸发器入口 ) / (U 蒸发器2Φ ·A 总 ·ΔT 对数平均蒸发器2Φ );

[0187] The ratio of the area percentage of steam to that of both phases can be calculated as follows:

[0188] %A 蒸汽 / %A 蒸发器2Φ =(h 蒸发器出口 -h 蒸发器饱和 )·U 蒸发器2Φ ·ΔT 对数平均蒸发器2Φ / [(h 蒸发器饱和 -h 蒸发器入口 )·U 蒸发器蒸汽·ΔT 对数平均蒸汽 ];

[0189] %A 蒸汽 +%A 蒸发器2Φ =1.

[0190] The logarithmic mean temperature difference for each region can be calculated as follows:

[0191] ΔT 对数平均蒸发器2Φ =[ΔT 对数平均蒸发器2Φ设计 / (h 蒸发器饱和 -h 蒸发器入口 ) 设计 ]·(h 蒸发器饱和 -h 蒸发器入口 );as well as

[0192] ΔT 对数平均蒸发器蒸汽 =[ΔT 对数平均蒸发器蒸汽设计 / (h 蒸发器出口 -h 蒸发器饱和 ) 设计 ]·(h 蒸发器出口 -h 蒸发器饱和 ).

[0193] The calculations described herein can be performed by the control module. The calculation of the total indoor charge can be accomplished using the characteristics of the refrigerant specific volume. Specific volume can be approximately linearly correlated with the enthalpy within each phase zone, thus allowing for the calculation of a reliable average specific volume of the phase zone at the inlet and outlet. The evaporator refrigerant mass is calculated by the control module by combining this with the percentage of the evaporator heat transfer area used for two-phase heat transfer and vapor superheating. Given the liquid density and liquid line volume upstream of the expansion unit, the liquid line refrigerant mass can be calculated by the control module to estimate the indoor refrigerant charge (e.g., mass) according to the following equations:

[0194] Indoor refrigerant charge mass = refrigerant mass in liquid pipeline + refrigerant mass in evaporator;

[0195] in,

[0196] Refrigerant mass in liquid pipeline = V 液体 / v 液体 ;as well as

[0197] Evaporator refrigerant mass = 2%A 2Φ ·V 蒸发器 / (v 蒸发器入口 +v 蒸发器饱和 )+2·%A 蒸汽 ·V 蒸发器 (v 蒸发器饱和 +v 蒸发器出口 ).

[0198] The control module can perform similar calculations to determine whether the condenser or outdoor unit (M) is suitable. 室外 ) quantity (e.g., mass m) to observe the total mass (M) 室内 +M 室外 The control module can determine the presence of a leak based on changes in total mass. Alternatively, the control module can use the amount measured on the outdoor side to determine when a leak exists in the system. In the absence of a charge reservoir such as an accumulator or receiver, less than 4 ounces of charge removal can be observed in the calculation.

[0199] The control module can use the calculated room charge to verify during operation that the room charge remains below a predetermined amount (M1) as determined by the refrigerant concentration limit (RCP). The RCP limit can be 25% of the lower flammability limit of A2L refrigerant and other flammable refrigerants. By using a charge isolation valve, the (e.g., total) charge at the end of the turn-on cycle remains constant during the turn-off cycle.

[0200] In summary, the control module can control the isolation valve to maintain the refrigerant charge (e.g., indoor) below a predetermined amount (M1) within the occupied building. The amount of refrigerant within the system can be determined using other methods, such as based on system installation, commissioning, continuous commissioning, service contract monitoring, and service. Indoor charge M 室内 (i.e., quality) can be determined to be below the predetermined amount (M1) or another suitable amount permitted according to one or more provisions.

[0201] The refrigerant in the vapor compression system can be a refrigerant such as R-410A, R-32, R-454B, R-444A, R-404A, R-454A, R-454C, R-448A, R-449A, R-134a, R-1234yf, R-1234ze, R-1233zd, or other types of refrigerants. The properties of the refrigerant used to determine its density and volume can be calculated by the control module based on measured values ​​and the properties of the refrigerant.

[0202] Evaporators and condensers (heat exchangers) may include finned tubes, concentric brazed plates, plate frames, microchannels, or other heat exchangers with (e.g., constant) internal volumes. As discussed above, there may be a single evaporator and condenser or multiple parallel evaporators or condensers. Refrigerant flow may be controlled by capillary tubes, thermostatic expansion valves, electrostatic expansion valves, or other methods.

[0203] As mentioned above Figure 4 As detailed, the amount of refrigerant can be determined by the control module based on the measurement results from pressure and temperature sensors, such as... Figure 6 As shown. Figure 6A method is provided for controlling an isolation valve based on a calculated refrigerant charge to isolate refrigerant charge in the outdoor components of a refrigeration system. Some type of isolation control may exist on both the liquid and suction lines, including at least one of a dedicated isolation valve, a positive-seat compressor, a suction check valve, and a positive-seat electronic expansion valve. Isolation valve control may be automatic or responsive to changes in the operating state of the control system and the identification of leaks.

[0204] Isolation valves 20 and 22 can be actuated (e.g., closed) by the control module at the end of an operating cycle (e.g., when the refrigeration system is shut off) to ensure, for example, that the indoor refrigerant charge does not exceed a predetermined amount (M1). When the refrigeration system starts, isolation valves 20 and 22 are opened by the control module. This allows compressor 12 to be started via the control module. When the refrigeration system is off, the refrigerant charge balance between the indoor and outdoor sections can be controlled by the control module through control, for example, auxiliary heating or cooling. This allows for a shorter period of instability and lower (compressor) capacity at the start of an operating cycle (e.g., when the refrigeration system is turned on). This reduces energy loss caused by the refrigeration system's operating (on / off) cycles. The control module maintains the indoor refrigerant charge below a predetermined amount (M1).

[0205] exist Figure 6 In the example, when a leak is detected, the control module closes isolation valves 20 and 22 to isolate refrigerant charge outside the building, preventing continued refrigerant leakage inside the building. When the compressor is running, the liquid-side isolation valve 22 can be closed by the control module, while the suction-side isolation valve remains open when a leak is detected. This allows refrigerant to be pumped out and isolated outside the building. The control module can operate the compressor and keep the suction-side isolation valve open, for example, until a predetermined suction pressure and / or a predetermined evaporator temperature is reached. This can indicate that a predetermined amount (M1) has been reached indoors. The control module can shut off the compressor and close all isolation valves. Isolation valves 20 and 22 close sequentially before the end of the operating cycle to allow the valve closure to be time-aligned with the end of the cycle. Manual or automatic actuation of the isolation valves allows system isolation for maintenance or commissioning. In various implementations, the isolation valves can be condenser unit valves retrofitted with (electronic) automatic actuators.

[0206] The control module can perform pumping during commissioning, for example, to establish volume in the chamber sections of isolation valves 20 and 22 and to fill or liquid lines in the operating chambers. Volume data can be stored for future reference, such as for filling calculation equations.

[0207] For example, during practical testing of the pumping technology described herein in a residential HVAC system charged with 15 lbs (8 oz) of refrigerant, 3 lbs. 4 oz. of refrigerant was pumped from the indoor section of the HVAC system to the outdoor section after the HVAC system was not pumped. In an HVAC system charged with 15 lbs. 8 oz. of refrigerant, 1 lb. 6. 2 oz. of refrigerant was pumped out (recovered) from the indoor section of the HVAC system after 15 seconds of pumping operation. Finally, in an HVAC system charged with 15 lbs. 8 oz. of refrigerant, only 7.2 oz. of refrigerant was recovered from the indoor section of the HVAC system after the system was not pumped.

[0208] Reference Figure 7 A functional block diagram of an example refrigeration system 10B, including isolation valves and pressure and temperature sensors, is provided. Figure 7 As shown, the refrigeration system includes a compressor 12 and a condenser 14 located outside (i.e., outdoors) of building 15. An expansion valve 16 and an evaporator 18 are located inside (i.e., indoors) of building 15.

[0209] For example, the first isolation valve 20 is located outside the building and between the evaporator 18 and the compressor 12. For example, the second isolation valve 22 is located outside the building and between the condenser 14 and the expansion valve 16.

[0210] A fan 100 is positioned adjacent to the evaporator 18 and blows air across the evaporator 18 when switched on. A first control module 102 controls the operation of the fan 100. A second control module 104 calculates the indoor and outdoor charge amounts, for example, based on measurements from a first temperature sensor 106 and a first pressure sensor 108 located between the evaporator 18 and the compressor 12, and a second temperature sensor 110 located between the condenser 14 and the expansion valve 16. When the refrigeration system is switched on, the control module can determine the indoor and outdoor charge amounts. If the total system charge amount decreases, the control module can determine that a leak exists. The control module can determine the total (or overall) system charge amount, for example, based on or equal to the sum of the indoor and outdoor charge amounts.

[0211] If a leak is detected, the second control module 104 can initiate pumping. This may include the second control module 104 closing the second isolation valve 22 and operating the compressor 12. This can pump refrigerant from the indoor side I of the refrigeration system to the outdoor side O. When pumping is complete, the second control module 104 can close the first isolation valve 20 and shut off the compressor to isolate the outdoor portion O of the system from the indoor portion I of the system. The second control module 104 may prompt the first control module 102 to activate the fan 100 and / or one or more other mitigation devices, for example, to disperse / dilute any leaked refrigerant within the building. The pressure sensor 108 can be used to detect leaks by detecting a pressure drop from the indoor side of the system 10B.

[0212] Reference Figure 8 The diagram presents a functional block diagram of an example implementation of a refrigeration system 10C. The refrigeration system may include a compressor 12 and a condenser 14 located outside the building 15 (i.e., outdoors). An expansion valve 16 and an evaporator 18 are located inside the building 15 (i.e., indoors).

[0213] For example, the first isolation valve 20 is located inside the building and between the evaporator 18 and the compressor 12. For example, the second isolation valve 22 is located outside the building and between the condenser 14 and the expansion valve 16.

[0214] The fan 100 is positioned adjacent to the evaporator 18 and is controlled by the first control module 102. The second control module 104 can control the compressor 12 and the isolation valves 20, 22, for example, in response to a signal from the first control module 102.

[0215] A refrigerant leak sensor 120 is installed in the indoor unit and may be adjacent to the evaporator 18. The refrigerant leak sensor 120 can indicate whether a refrigerant leak exists. Figure 8 In the system, the first control module 102 receives a signal from the leak sensor 120 and communicates with the second control module 104 if a leak is detected. When a leak is detected, the second control module 104 initiates a pumping sequence. This may include closing the second isolation valve 22 and operating the compressor 12 to pump refrigerant from inside the building to outside. When pumping is complete, the second control module 104 closes the first isolation valve 20 and shuts off the compressor 12 to isolate the outdoor portion O of the system from the indoor portion I of the system.

[0216] The second control module 104 also communicates with the first control module 102, for example, to activate the fan 100 and / or one or more other mitigation devices, such as to disperse any leaking refrigerant or prevent / lock the operation of any ignition source. Isolation valves 20, 22, the compressor 12, or the expansion device 16 control the total refrigerant charge, for example, to minimize the charge or maintain the charge below a predetermined amount (M1) during both compressor operation and compressor non-operation periods.

[0217] Figure 9 This is a flowchart illustrating an example method for detecting refrigerant leaks using a leak sensor 120. Control begins at S200. At S202, the control module determines whether the measurement result from the leak sensor is greater than a predetermined value. For example, the leak sensor may measure the refrigerant concentration in the air. When the concentration (e.g., parts per million or parts per billion) is not greater than a predetermined concentration or amount, control continues to S204. In various implementations, a calibration amount may be subtracted from the predetermined value (or setpoint SP). At S204, the control module sets the counter value to zero, and control returns to S200. If the control module determines whether the measurement result from the sensor is greater than the predetermined value, control continues to S206.

[0218] At S206, the control module increments the counter value (e.g., by 1), and control continues to S208. At S208, the control module determines whether the counter value is greater than a predetermined value. If S208 is true, the control module determines and indicates the presence of a leak at S210, and control returns to S200. If S208 is false, the control module can determine that no leak exists, and control returns to S200. The predetermined value is greater than zero and can be greater than 1. By requiring the counter value to be greater than 1, control ensures the presence of an actual leak by requiring measurements from multiple consecutive sensor readings to be greater than the predetermined value. This avoids harmful alarms / lockdowns regarding leaks.

[0219] Figure 10 This is a functional block diagram of an example refrigeration (e.g., air conditioning) system 10D. System 10D includes a compressor 12 and a condenser 14 located outside (i.e., outdoors) of building 15, and an expansion valve 16 and an evaporator 18 located inside (i.e., indoors) of building 15.

[0220] The first isolation valve 20 is located outside, for example, building 15, and between the evaporator 18 and the compressor 12. The second isolation valve 22 is located outside, for example, building 15, and between the condenser 14 and the expansion valve 16.

[0221] Fan 100 is positioned adjacent to evaporator 18 and can be controlled by first control module 102. When switched on, fan 100 blows air across evaporator 18. Second control module 104 can control compressor 12 and isolation valves 20, 22.

[0222] exist Figure 10 In the example, the first control module 102 communicates with the second control module 104 to indicate whether cooling is required. For example, when cooling is required, the first control module 102 can set the signal to a first state, and when cooling is not required, it can set the signal to a second state. Although an example of separate control modules (the first control module and the second control module) has been described herein, in various implementations, multiple control modules can be integrated within a single control module.

[0223] The second control module 104 can selectively perform pumping, for example, when a leak is detected or cooling demand is stopped. Pumping may include the second control module 104 closing the second isolation valve 22 and keeping the compressor 12 on for a predetermined period of time. After the predetermined period of time, the second control module 104 may close the first isolation valve 20 and shut down the compressor 12. This isolates the refrigerant in the outdoor section O of the system and isolates the refrigerant from the indoor section I. This ensures that the amount of refrigerant in the indoor section I is less than a predetermined amount (M1) when the compressor 12 is turned off.

[0224] Figure 11 A functional block diagram of an example refrigeration (e.g., air conditioning) system 10E is shown. The system 10E includes a compressor 12 and a condenser 14 located outside (i.e., outdoors) of building 15 and an expansion valve 16 and an evaporator 18 located inside (i.e., indoors) of building 15.

[0225] The first isolation valve 20 is located outside, for example, building 15, and between the evaporator 18 and the compressor 12. The second isolation valve 22 is located outside, for example, building 15, and between the condenser 14 and the expansion valve 16.

[0226] Fan 100 is positioned adjacent to evaporator 18 and can be controlled by first control module 102. When switched on, fan 100 blows air across evaporator 18, for example, to cool the air inside building 15. Second control module 104 can control compressor 12 and isolation valves 20, 22.

[0227] The first control module 102 communicates with the second control module 104 to indicate whether cooling is required, as described above. The second control module 104 can selectively perform pumping, for example, when the cooling demand ceases. This may include the second control module 104 closing the second isolation valve 22 and keeping the compressor 12 on for a predetermined period after the cooling demand has ended. Once the predetermined period has elapsed, the second control module 104 can shut off the compressor 12 and close the first isolation valve 20. This isolates the refrigerant in the outdoor section O of the system such that when the compressor 12 is shut off, the amount of refrigerant in the indoor section I is less than a predetermined amount (M1).

[0228] Pressure sensor 108 may be disposed between evaporator 18 and first isolation valve 20. Alternatively or additionally, pressure sensor (or pressure sensor 108) may be disposed between expansion valve 16 and isolation valve 22.

[0229] When the system is shut down (e.g., the isolation valve closes and compressor 12 shuts down), pressure sensor 108 measures the pressure in indoor section I, such as pressure decay. When the pressure (or absolute value of the pressure) measured by pressure sensor 108 decays (e.g., decreases by at least a predetermined amount), second control module 104 can determine and indicate the presence of a refrigerant leak. Upon detecting a leak, second control module 104 can prompt first control module 102 to activate fan 100. The control module can also activate one or more other mitigation devices to disperse / dilute the refrigerant within the building.

[0230] Figure 12 This is a functional block diagram of an example refrigeration (e.g., air conditioning) system 10F. The system 10F is shown, including a compressor 12 and a condenser 14 located outside the building 15 (i.e., outdoors), and an expansion valve 16 and an evaporator 18 located inside the building 15 (i.e., indoors).

[0231] A fan 100 is positioned adjacent to the evaporator 18 and can be controlled by a first control module 102. When switched on, the fan 100 blows air across the evaporator 18, as described above. A second control module 104 can control the compressor 12. The second control module 104 can calculate indoor and outdoor charge amounts based on measurements from a first temperature sensor 106 and a first pressure sensor 108 located between the evaporator 18 and the compressor 12, and based on measurements from a second temperature sensor 110 and a second pressure sensor 112 located between the condenser 14 and the expansion valve 16. Based on the measurements from the pressure sensors 108, 112 and the temperature sensors 106, 110, the indoor and outdoor charge levels can be calculated when the HVAC system is switched on (e.g., the compressor is switched on and the isolation valve is open). The second control module 104 can determine the indoor charge amount, for example, using an equation or lookup table that correlates the measured pressure and temperature with the indoor charge amount. The second control module 104 can determine the outdoor charge amount, for example, using an equation or lookup table that correlates the measured pressure and temperature with the outdoor charge amount.

[0232] The second control module 104 can determine the overall (total) system charge based on the indoor and outdoor charge volumes. The second control module 104 can determine the total charge volume, for example, using an equation or lookup table that correlates the indoor and outdoor charge volumes with the total charge volume. For example, the second control module 104 can set the total charge volume based on or equal to the indoor charge volume plus the outdoor charge volume.

[0233] If the total refrigerant charge decreases, the second control module 104 can determine and indicate the presence of a leak. If a leak is detected, the second control module 104 can shut down the compressor 12. The second control module 104 can also prompt the first control module 102 to turn on the fan 100. The control module can also activate one or more other mitigation devices to dilute / disperse any leaked refrigerant.

[0234] Figure 13 This is a functional block diagram of an example refrigeration (e.g., air conditioning) system 10G. The system 10G is shown including a compressor 12 and a condenser 14 located outside the building 15 (i.e., outdoors), and an expansion valve 16 and an evaporator 18 located inside the building 15 (indoors).

[0235] The first isolation valve 20 is located between the evaporator 18 and the compressor 12. The second isolation valve 22 is located, for example, outside a building, between the condenser 14 and the expansion valve 16. The control module 102 controls the compressor 12 and the isolation valves 20 and 22.

[0236] Control module 102 receives signals from a pair of pressure sensors and / or a pair of temperature sensors 130A, 130B that measure across expansion valve 16 (i.e., on opposite sides of it). When isolation valves 20, 22 and expansion valve 16 are closed, control module 102 monitors the measurements from temperature and / or pressure sensors 130A, 130B to determine if there is leakage through the expansion valve. For example, control module 102 can determine if there is leakage through the expansion valve when the temperature and / or pressure (e.g., at expansion valve 16) changes by at least a predetermined amount. Because isolation valves 20 and 22 and expansion valve 16 should be closed, leakage through expansion valve 16 may exist when the temperature difference and / or pressure difference across the expansion valve, as measured by sensors 130A, 130B, changes by at least a predetermined amount when valves 20, 22, and 16 are closed.

[0237] A leak in expansion valve 16 causes cooling of the refrigerant downstream of expansion valve 16. When a leak is detected, control module 102 may activate a fan (e.g., fan 100) that blows air across evaporator 18 and / or one or more other mitigation devices. Control module 102 may additionally shut off or lock any ignition source.

[0238] exist Figure 13 In the example, positive-seal isolation valves 20 and 22 are used. To verify that the leak is through expansion valve 16 and not the isolation valve, control module 102 can perform one or more diagnostics to verify that isolation valves 20 and 22 are not leaking. Pressure or temperature sensors 130A and 130B are installed to observe the saturation temperature or pressure of the isolation refrigerant in relation to ambient temperature or pressure during non-operating periods.

[0239] Reference Figure 14 A functional block diagram of an example refrigeration (e.g., air conditioning) system 10H is provided. The system 10H is shown to include a compressor 12 and a condenser 14 located outside the building 15 (i.e., outdoors), and an expansion valve 16 and an evaporator 18 located inside the building 15 (i.e., indoors).

[0240] The first pair of isolation valves 20A and 20B are located between the evaporator 18 and the compressor 12, with one isolation valve 20A located on the outdoor side and the other isolation valve 20B located on the indoor side. The second pair of redundant isolation valves 22A and 22B are located between the condenser 14 and the expansion valve 16, with one isolation valve 22A located on the outdoor side and the other isolation valve 22B located on the indoor side.

[0241] Control module 102 controls compressor 12 and isolation valves 20A, 20B, 22A, and 22B. Control module 102 receives measurement results from temperature sensors 130A, 130B, and 130C. Temperature sensor 130A is located upstream of isolation valves 20A and 20B (and measures therebetween), between evaporator 18 and isolation valve 20B. Temperature sensor 130B is located between isolation valves 20A and 20B (and measures therebetween). Temperature sensor 130C is located downstream of isolation valves 20A and 20B (and measures therebetween), between isolation valve 20A and compressor 12. Control module 102 also receives measurement results from temperature and / or pressure sensors 132A, 132B, and 132C. Sensor 132A is located upstream of isolation valves 22A and 22B (and measures therebetween), between condenser 14 and isolation valve 22A. Sensor 132B is positioned between isolation valves 22A and 22B (and performs measurements therebetween). Sensor 132C is positioned downstream of isolation valves 22A and 22B (and performs measurements therebetween), located between isolation valve 22B and evaporator 18.

[0242] With isolation valves 20 and 22 and expansion valve 16 all closed, control module 102 monitors the measurement results from sensors 130A, 130B, 130C, 132A, 132B, and 132C to determine if a leak exists. Control module 102 can determine the presence of a leak when the difference between one or more measurement results or between two or more measurement results changes by at least a predetermined value. If so, control module 102 can confirm the existence of a leak.

[0243] When a leak is detected, control module 102 can activate a fan (e.g., fan 100) and / or one or more other mitigation devices. This may disperse or dilute any leaking refrigerant. Redundant isolation valves 20B and 22B can be used to provide additional protection to isolate the refrigerant outside the building.

[0244] According to another method of this disclosure, a pump-out (removal) procedure can be performed at the end of the cooling season (e.g., on a predetermined date and time, such as October 1st in the Northern Hemisphere). This allows low-level leakage to return through an isolation valve to the indoor coils of the HVAC system with charge isolation. Additionally or alternatively, the pump-out procedure can be performed when the cooling system has been continuously shut down for a predetermined number of days (e.g., 14 days or another suitable number of days). The standard maximum leakage rate of the isolation valve at shutdown can be a predetermined value. The control module can track the period since the last pumping while the system is continuously shut down and perform another pumping to prevent the indoor charge from exceeding a predetermined amount (M1) based on the standard maximum leakage rate.

[0245] Figure 15This is a functional block diagram of an example control system including control module 500, such as one or more of the control modules described above. The filling module 504 determines the indoor filling amount, the outdoor filling amount, and / or the total filling amount, as described above. The filling module 504 determines these amounts based on measurements from one or more sensors 508, as described above.

[0246] Leakage module 512 diagnoses the presence of a leak, as described above. Leakage module 512 can determine the presence of a leak based on measurements from one or more sensors 508, indoor fill level, outdoor fill level, and / or total fill level, as described above. When a leak is present, alarm module 516 generates one or more indicators. For example, alarm module 516 can send indications to one or more external devices 520, generate one or more visual indications 524 (e.g., turning on one or more lights, displaying information on one or more displays, etc.), or generate one or more audible indications, such as via one or more speakers 528.

[0247] As described above, isolation module 532 controls the opening and closing of isolation valve 536 in the refrigeration system. As described above, compressor module 540 controls the operation (e.g., on / off) of one or more compressors 544. Compressor module 540 can also control the speed, capacity, etc., of one or more compressors 544. Pumping module 548 selectively performs pumping, as described above. As described above, expansion module 552 can control the opening and closing of one or more expansion valves 556. These modules can communicate and cooperate to perform the corresponding operations described above. For example, isolation module 532, expansion module 552, and compressor module 540 can control the isolation valve, expansion valve, and compressor as described above to determine if a leak exists in order to perform pumping, etc.

[0248] This disclosure also provides a method for controlling the operation of components based on the operation of isolation valves 20, 22 and calculations of refrigerant charge, said components including but not limited to compressor 12, expansion device 16, flow device or other components of vapor compression system, wherein thermostats or other control methods may be overridden (i.e., system shutdown) based on charge calculations indicating the presence of a leak.

[0249] This disclosure also provides a processing unit that controls the sequence of isolation valves, component operation, and processes sensor inputs to calculate the system refrigerant charge, including but not limited to compressor 12, expander 16, flow devices, or other components of the vapor compression system. The processing unit has the capability to communicate (send and receive) with recording, diagnostic, monitoring, programming, debugging, database services, or other devices. This processing can be performed locally relative to the condenser unit, locally relative to the furnace unit, or remotely relative to other processors in the HVAC / refrigeration system and / or other remote processors.

[0250] The foregoing description is illustrative in nature and is in no way intended to limit the scope of this disclosure, its application, or its uses. The broad teachings of this disclosure can be implemented in various forms. Therefore, although this disclosure includes specific examples, its true scope should not be limited thereto, as other modifications will become apparent upon examination of the drawings, specification, and appended claims. It should be understood that one or more steps within the method may be performed in a different order (or simultaneously) without altering the principles of this disclosure. Furthermore, although each embodiment is described above as having certain features, any one or more of those features described with respect to any embodiment of this disclosure may be implemented and / or combined with features of any other embodiment, even if such combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the substitution of one or more embodiments for each other remains within the scope of this disclosure.

[0251] Various terms are used to describe spatial and functional relationships between components (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connection," "joint," "coupled," "adjacent," "next to," "on top," "above," "below," and "set." Unless explicitly described as "direct," when describing the relationship between a first component and a second component in the foregoing disclosure, the relationship can be a direct relationship where no other intervening components exist between the first and second components, or it can be an indirect relationship (spatially or functionally) between the first and second components. As used herein, the phrase at least one of A, B, and C should be interpreted as meaning the use of a non-exclusive logical OR (A or B or C) logic and should not be interpreted as meaning "at least one of A, at least one of B, and at least one of C."

[0252] In the accompanying drawings, the direction of the arrows, as indicated by the arrows, typically indicates the flow of information important to the illustration (such as data or instructions). For example, when components A and B exchange various information, but the information transmitted from component A to component B is relevant to the illustration, the arrow can point from component A to component B. This unidirectional arrow does not imply that no other information is being transmitted from component B to component A. Furthermore, for information sent from component A to component B, component B may send a request for the information or a confirmation of receipt of the information to component A.

[0253] In this application, which includes the definitions below, the terms "module" or "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include the following: application-specific integrated circuit (ASIC); digital, analog, or mixed-signal analog / digital discrete circuit; digital, analog, or mixed-signal analog / digital integrated circuit; combinational logic circuit; field-programmable gate array (FPGA); processor circuitry (shared, dedicated, or grouped) that executes code; memory circuitry (shared, dedicated, or grouped) that stores code executed by the processor circuitry; other suitable hardware components that provide the aforementioned functionality; or a combination of some or all of the above, such as in a system-on-a-chip.

[0254] A module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module in this disclosure may be distributed across multiple modules connected via the interface circuits. For example, multiple modules may allow for load balancing. In another example, a server (also known as a remote or cloud) module may perform some functions on behalf of a client module.

[0255] The term "code," as used above, can include software, firmware, and / or microcode, and can refer to programs, routines, functions, categories, data structures, and / or objects. The term "shared processor circuitry" includes a single-processor circuitry that executes some or all of the code from multiple modules. The term "grouped processor circuitry" includes processor circuitry that is combined with other processor circuitry to execute some or all of the code from one or more modules. References to multiprocessor circuitry include multiprocessor circuitry on a discrete chip, multiprocessor circuitry on a single chip, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term "shared memory circuitry" includes a single memory circuitry that stores some or all of the code from multiple modules. The term "grouped memory circuitry" includes memory circuitry that is combined with other memory to store some or all of the code from one or more modules.

[0256] The term memory circuit is a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not include transient electrical or electromagnetic signals propagating through a medium (e.g., on a carrier wave), and therefore the term computer-readable medium can be considered 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 magnetic tape or digital magnetic tape or hard disk drives), and optical storage media (e.g., CDs, DVDs, or Blu-ray discs).

[0257] The apparatus and methods described in this application can be implemented, partially or completely, 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 aforementioned function blocks, flowchart components, and other elements serve as software specifications, which can be compiled into a computer program through the routine work of an experienced technician or programmer.

[0258] 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 depend 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 the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0259] Computer programs can include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation); (ii) assembly code; (iii) object code generated by a compiler from source code; (iv) source code executed by an interpreter; (v) source code compiled and executed by a just-in-time (JIT) compiler, etc. As examples only, programs from languages ​​including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, and Lisp can be used. Fortran, Perl, Pascal, Curl, OCaml, HTML5 (Hypertext Markup Language 5th Edition), Ada, ASP (Dynamic Server-Side Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Visual Lua, MATLAB, SIMULINK and Use the syntax of the language to write source code.

Claims

1. A refrigerant control system, comprising: A charging module configured to determine the amount of refrigerant present in the building's refrigeration system; A leakage module configured to diagnose a leak in the refrigeration system based on the amount of refrigerant. An isolation module, configured to respond to the diagnosis of a leak in the refrigeration system: Close the first isolation valve located downstream of the first heat exchanger outside the building and between the first heat exchanger and the second heat exchanger inside the building; as well as The second isolation valve, positioned downstream of the second heat exchanger outside the building and between the second heat exchanger and the compressor of the refrigeration system, remains open. as well as A compressor module configured to operate the compressor of the refrigeration system for a predetermined period of time in response to a diagnostic of a leak in the refrigeration system, with the first isolation valve closed and the second isolation valve open. The isolation module is further configured to close the second isolation valve in response to confirmation that the predetermined time period has elapsed. The charging module is configured to determine the amount of refrigerant in the refrigeration system based on the volume of a first heat exchanger located outside the building, the volume of a second heat exchanger located inside the building, and the volume of the refrigerant pipeline of the refrigeration system. The charging module is configured to determine the volume of the first heat exchanger based on at least one temperature and at least one pressure of the refrigerant in the refrigeration system and the volumetric flow rate of the compressor of the refrigeration system.

2. The refrigerant control system according to claim 1, wherein, The charging module is configured to determine the volume of the refrigerant line based on at least one second temperature, at least one second pressure of the refrigerant within the refrigeration system, and the volumetric flow rate of the compressor of the refrigeration system.

3. The refrigerant control system according to claim 1, wherein, The leakage module is configured to diagnose a leak in the refrigeration system based on measurements from a leakage sensor located at one of the first and second heat exchangers in the refrigeration system.

4. The refrigerant control system according to claim 1, wherein, The leak module is configured to diagnose a leak in the refrigeration system when the pressure of the refrigerant in the building, as measured by a pressure sensor within the building, decreases.

5. The refrigerant control system according to claim 1, further comprising: An alarm module is configured to generate an alarm via a visual indicator in response to a diagnosis of a leak in the refrigeration system.

6. The refrigerant control system according to claim 1, further comprising: An alarm module is configured to send an alarm to an external device via a network in response to a diagnosis of a leak in the refrigeration system.

7. The refrigerant control system according to claim 1, wherein, The filling module is configured to: Determine a first amount of refrigerant present in a first portion of the refrigeration system located within the building; Determine a second quantity of refrigerant present in a second part of the refrigeration system located outside the building; The amount of refrigerant in the refrigeration system is determined based on a first amount of refrigerant in the first part and a second amount of refrigerant in the second part. as well as The leakage module is configured to diagnose a leak in the refrigeration system based on at least one of the following: a first amount of refrigerant, a second amount of refrigerant, and the amount of refrigerant.

8. A refrigerant control method, comprising: Determine the amount of refrigerant present in the building's refrigeration system; The presence of a leak in the refrigeration system is diagnosed based on the amount of refrigerant. In response to the diagnosis of a leak in the refrigeration system: close the first isolation valve located downstream of the first heat exchanger outside the building and between the first heat exchanger and the second heat exchanger inside the building; The second isolation valve, positioned downstream of the second heat exchanger outside the building and between the second heat exchanger and the compressor of the refrigeration system, remains open. as well as With the first isolation valve closed and the second isolation valve open, the compressor of the refrigeration system is operated for a predetermined period of time; as well as In response to the confirmation that the predetermined time period has elapsed, the second isolation valve is closed. Determining the quantity includes: The amount of refrigerant in the refrigeration system is determined based on the volume of the first heat exchanger located outside the building, the volume of the second heat exchanger located inside the building, and the volume of the refrigerant pipeline of the refrigeration system; and The volume of the first heat exchanger is determined based on at least one temperature and at least one pressure of the refrigerant within the refrigeration system and the volumetric flow rate of the compressor of the refrigeration system.

9. The refrigerant control method according to claim 8, wherein, The diagnosis includes diagnosing a leak in the refrigeration system based on measurements from a leak sensor located at one of the first and second heat exchangers in the refrigeration system.

10. The refrigerant control method according to claim 8, wherein, The diagnosis includes diagnosing a leak in the refrigeration system when the pressure of the refrigerant in the building, as measured by a pressure sensor within the building, decreases.

11. The refrigerant control method according to claim 8, further comprising at least one of the following: Alarms are generated via visual indicators; and Send alerts to external devices via the network.

12. The refrigerant control method according to claim 8, wherein, Determining the quantity includes: Determine a first amount of refrigerant present in a first portion of the refrigeration system located within the building; Determine a second quantity of refrigerant present in a second part of the refrigeration system located outside the building; The amount of refrigerant in the refrigeration system is determined based on a first amount of refrigerant in the first portion and a second amount of refrigerant in the second portion; and The diagnosis includes diagnosing a leak in the refrigeration system based on at least one of the following: a first amount of refrigerant, a second amount of refrigerant, and the amount of refrigerant.

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