Refrigerant leak sensor power control system and method

Abstract

The sensor control system includes a refrigerant leak sensor and a power control module that measure the amount of refrigerant present in the air outside the heat exchanger of the cooling system when power is supplied, wherein the heat exchanger is located within a building that is heated, cooled, or heated and cooled by the cooling system, and the power control module cuts off power to the refrigerant leak sensor when power is continuously supplied to the refrigerant leak sensor or when a blower that moves air to pass through the heat exchanger is turned on.

Description

Technology Field

[0001] The present disclosure relates to a refrigerant leak sensor, and more specifically, to a system and method for controlling the power of a refrigerant leak sensor.

[0002] <Cross-reference to related applications>

[0003] This application claims priority to U.S. Patent Application No. 17 / 036,448, filed on September 29, 2020. The full contents of the aforementioned application are incorporated herein by reference. Background Technology

[0004] The background art description provided herein is intended to generally present the context of the invention. The work of the inventors cited herein is not recognized as prior art, either expressly or impliedly, within the scope described in this background art section, nor are any aspects of the description that may not otherwise qualify as prior art at the time of filing acknowledged as such.

[0005] Cooling and air conditioning applications are under increased regulatory pressure to reduce the global warming potential of the refrigerants used. To use refrigerants with a low global warming potential, the flammability of the refrigerants may increase.

[0006] Several refrigerants have been developed that are considered options with a low potential for global warming, and these are classified as A2L in the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) classification, meaning slightly flammable. The UL (Underwriters Laboratory) 60335-2-40 standard and similar standards specify a specified (M1) level (or slightly flammable) for A2L refrigerants and indicate that leak detection and mitigation are not required at A2L refrigerant charge levels below the specified level. means of solving the problem

[0007] In one feature, the sensor control system comprises: a refrigerant leak sensor that measures the amount of refrigerant present in the air outside the heat exchanger of the cooling system when power is supplied; and a power control module, wherein the power control module ensures that power to the refrigerant leak sensor is not cut off while power is continuously supplied to the refrigerant leak sensor and power is received by the power control module, and the heat exchanger is located within a building that is heated, cooled, or heated and cooled by the cooling system.

[0008] In one feature, the sensor control system comprises: a refrigerant leak sensor that measures the amount of refrigerant present in the air outside the heat exchanger of the cooling system when power is supplied; and a power control module that cuts off power to the refrigerant leak sensor when a blower that moves air to pass through the heat exchanger is in the ON state, wherein the heat exchanger is located within a building that is heated, cooled, or heated and cooled by the cooling system.

[0009] In an additional feature, the power control module is configured to determine that the blower is in the ON state when the current to the electric motor of the blower is greater than a predetermined current.

[0010] In an additional feature, the power control module is configured to determine that the blower is in an ON state when the voltage applied to the electric motor of the blower is greater than a predetermined voltage.

[0011] In an additional feature, the power control module is configured to determine that the blower is in the ON state when the speed of the electric motor of the blower is greater than a predetermined speed.

[0012] In an additional feature, the power control module is configured to determine that the blower is in the ON state when the downstream air pressure of the heat exchanger is greater than a predetermined pressure.

[0013] In an additional feature, the power control module is configured to determine that the blower is turned on when the downstream air temperature of the heat exchanger is lower than a predetermined temperature during cooling.

[0014] In an additional feature, the power control module is configured to determine that the blower is turned on when the downstream air temperature of the heat exchanger is higher than a predetermined temperature during heating.

[0015] In an additional feature, the power control module is configured to determine that the blower is in the ON state when the air humidity on the downstream side of the heat exchanger is greater than a predetermined humidity.

[0016] In an additional feature, the power control module is configured to determine that the blower is in the ON state when the flow rate of air passing through the duct is greater than a predetermined flow rate.

[0017] In an additional feature, the power control module is configured to determine that the blower is in the ON state when a command to turn the blower on is received.

[0018] In terms of additional features, the refrigerant is classified as having low flammability.

[0019] In an additional feature, the power control module is configured to supply power to the refrigerant leak sensor when the blower is in the off state.

[0020] In addition to the features, the power control module supplies power to the refrigerant leak sensor during a first predetermined period of each second predetermined period while the blower is in an off state, and cuts off power to the refrigerant leak sensor during the remaining period of each second predetermined period, wherein the second predetermined period is greater than the first predetermined period.

[0021] In one feature, the sensor control system comprises: a refrigerant leak sensor that measures the amount of refrigerant present in the air outside the heat exchanger of the cooling system when power is supplied; and a power control module, wherein the heat exchanger is located within a building that is heated, cooled, or heated and cooled by the cooling system, and the power control module ensures that power is supplied to the refrigerant leak sensor during a first predetermined period of each second predetermined period and that power to the refrigerant leak sensor is cut off during the remainder of each second predetermined period, wherein the second predetermined period is greater than the first predetermined period.

[0022] In one feature, the sensor control method measures the amount of refrigerant present in the air outside the heat exchanger of the cooling system by means of a refrigerant leak sensor; and cuts off power to the refrigerant leak sensor when a blower that moves air to pass through the heat exchanger is in the ON state, wherein the heat exchanger is located within a building that is heated, cooled, or heated and cooled by the cooling system.

[0023] In an additional feature, the sensor control method further comprises determining that the blower is in an ON state when at least one of the following is true: when the current to the electric motor of the blower is greater than a predetermined current; when the voltage applied to the electric motor of the blower is greater than a predetermined voltage; when the speed of the electric motor of the blower is greater than a predetermined speed; when the downstream air pressure of the heat exchanger is greater than a predetermined pressure; when the downstream air temperature of the heat exchanger is lower than a predetermined temperature during cooling; when the downstream air temperature of the heat exchanger is higher than a predetermined temperature during heating; when the downstream air humidity of the heat exchanger is greater than a predetermined humidity; when the flow rate of air passing through the duct is greater than a predetermined flow rate; and when a command to turn the blower ON is received.

[0024] In terms of additional features, the refrigerant is classified as having low flammability.

[0025] In addition to the additional features, the sensor control method comprises supplying power to the refrigerant leak sensor when the blower is in the off state.

[0026] In addition, the sensor control method further comprises, while the blower is in an off state, supplying power to the refrigerant leak sensor during a first predetermined period among each second predetermined period and cutting off power to the refrigerant leak sensor during the remaining period among each second predetermined period, wherein the second predetermined period is greater than the first predetermined period.

[0027] Further areas of applicability of the present invention will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the invention. Brief explanation of the drawing

[0028] The present disclosure will be more fully understood from the detailed description and the accompanying drawings. Figure 1 is a functional block diagram of an exemplary cooling system. Figure 2 is a functional block of an exemplary part of the cooling system of Figure 1. FIG. 3 is a functional block diagram of an exemplary implementation of a control module. Figure 4 is a flowchart showing an exemplary method for power control of a refrigerant leak sensor. In drawings, reference numbers may be reused to identify similar and / or identical elements. Specific details for implementing the invention

[0029] Some refrigerants used in cooling systems may be classified as mildly flammable (e.g., A2L refrigerant). Cooling systems using mildly flammable refrigerants may include a refrigerant leak sensor configured to measure the amount of refrigerant present in the air outside the cooling system within the building where the cooling system is operated. This amount of refrigerant corresponds to the amount of refrigerant leaked out of the cooling system.

[0030] A refrigerant leak sensor can be pulsed on and off at a predetermined rate. However, pulsed on and off of the refrigerant leak sensor may shorten the lifespan of the refrigerant leak sensor. For example, one or more optical components (e.g., a light bulb) of the refrigerant leak sensor may be damaged each time the refrigerant leak sensor is turned on. Therefore, pulsed on / off of the refrigerant leak sensor may shorten the lifespan of the refrigerant leak sensor.

[0031] According to the present application, a power control module can keep the refrigerant leak sensor continuously in the ON state. This can increase the lifespan of the refrigerant leak sensor. Alternatively, the power control module can keep the refrigerant leak sensor in the ON state and turn it OFF only when measurements from the refrigerant leak sensor are not required, such as when the blower is in the ON state. When the blower is in the ON state, the possibility of leakage can be mitigated.

[0032] FIG. 1 is a functional block diagram of an exemplary refrigeration system (100) comprising a compressor (102), a condenser (104), an expansion valve (106), and an evaporator (108). The refrigeration system (100) may include additional and / or alternative components such as a reversing valve or a filter-drier. Additionally, the present disclosure may be applicable to other types of refrigeration systems, including but not limited to heating, ventilating, and air conditioning (HVAC) systems, heat pump systems, refrigeration systems, and chiller systems. For example, the refrigeration system (100) may include a reversing valve (not shown) configured to switch the direction of refrigerant flow in a heat pump system.

[0033] The compressor (102) receives the refrigerant in vapor form and compresses the refrigerant. The compressor (102) provides the pressurized refrigerant in vapor form to the condenser (104). The compressor (102) includes an electric motor that drives a pump. For example, the pump of the compressor (102) may include a scroll compressor and / or a reciprocating compressor.

[0034] All or part of the pressurized refrigerant is converted into a liquid form within a condenser (104). The condenser (104) removes heat from the refrigerant and cools the refrigerant accordingly. When the refrigerant vapor is cooled to a temperature lower than the saturation temperature, the refrigerant is converted into a liquid (or liquefied) refrigerant. The condenser (104) may include an electric fan that increases the rate at which heat is removed from the refrigerant.

[0035] The condenser (104) supplies refrigerant to the evaporator (108) through the expansion valve (106). The expansion valve (106) controls the flow rate at which the refrigerant is supplied to the evaporator (108). The expansion valve (106) may include a thermostatic expansion valve and, for example, may be electronically controlled by a control module (130). The pressure drop caused by the expansion valve (106) may cause a portion of the liquefied refrigerant to be converted back into vapor form. In this way, the evaporator (108) can accommodate a mixture of refrigerant vapor and liquefied refrigerant.

[0036] In the evaporator (108), the refrigerant absorbs heat. When the liquid refrigerant is heated to a temperature higher than the refrigerant's saturation temperature, it is converted into a vapor form. The evaporator (108) may include an electric fan that increases the rate of heat transfer to the refrigerant.

[0037] The utility (120) provides power to the cooling system (100). For example, the utility (120) may provide single-phase AC power with a root mean squared (VRMS) value of about 230 volts. In other implementations, the utility (120) may provide three-phase AC power of approximately 400 VRMS, 480 VRMS, or 600 VRMS at a line frequency of, for example, 50 or 60 Hz. If the three-phase AC power is nominally 600 VRMS, the actual usable power voltage may be 575 VRMS.

[0038] The utility (120) may provide AC power to the control module (130) through an AC line containing two or more conductors. The AC power may also be provided to the drive (132) through the AC line. The control module (130) controls the cooling system (100). For example, the control module (130) may control the cooling system (100) based on user input and / or parameters measured by various sensors (not shown). Sensors may include pressure sensors, temperature sensors, current sensors, voltage sensors, etc. Sensors may also include feedback information from drive control, such as motor current or torque, through a serial data bus or other suitable data bus.

[0039] The user interface (134) provides user input to the control module (130). The user interface (134) may additionally or alternatively provide user input directly to the drive (132). User input may include, for example, a desired temperature, a request regarding the operation of the fan (e.g., a request for continuous operation of the evaporator fan), and / or other appropriate inputs. The user interface (134) may take the form of a thermostat, and some or all of the functions of the control module (e.g., including heat source operation) may be integrated into the thermostat.

[0040] The control module (130) can control the operation of the fan of the condenser (104), the fan of the evaporator (108), and the expansion valve (106). The control module (130) can also control the operation of the switching valve.

[0041] The drive (132) can control the compressor (102) based on a command from the control module (130). For example, the control module (130) can instruct the drive (132) to operate the motor of the compressor (102) at a constant speed or to operate the compressor (102) at a specific capacity. In various implementations, the drive (132) can also control the condenser fan.

[0042] The evaporator (108) may be located within the building where the cooling system is operated. The condenser (104) may be located outside the building. Depending on whether the heat pump system is to heat or cool within the building, the functions of the evaporator (108) and the condenser (104) are switched. When cooling is performed, the condenser (104) and the evaporator (108) perform as described above. When heating is performed, the flow of the cooling water is reversed so that the condenser (104) and the evaporator (108) operate in opposite directions. Therefore, the condenser (104) and the evaporator (108) may more generally be referred to as heat exchangers.

[0043] A refrigerant leak sensor (140) is placed inside the building and measures the amount (e.g., concentration) of refrigerant in the air (outside the cooling system) present at the refrigerant leak sensor. The refrigerant leak sensor (140) may be located, for example, near the evaporator (108), downstream of a blower that blows air across the evaporator (108) and into the building through a duct. The refrigerant leak sensor (140) may also be located downstream of the evaporator (108).

[0044] The refrigerant leak sensor (140) generates a signal based on the measured amount of refrigerant. For example, the refrigerant leak sensor (140) can transmit the amount of refrigerant to the control module (130). Alternatively, the refrigerant leak sensor (140) can set a signal to a first state when the amount of refrigerant exceeds a predetermined amount, and set a signal to a second state when the amount of refrigerant is less than the predetermined amount. The above-mentioned specified amount may be, for example, 25% of the lower flammability level of the refrigerant or other appropriate value. In various implementations, the refrigerant is classified as weakly flammable according to one or more standards. For example, the refrigerant may be classified as an A2L refrigerant or, more generally, weakly flammable as discussed above. The classification may be, for example, the standard of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the Underwriters Laboratory (UL) 60335-2-40 standard, or other standards by ASHRAE, UL, or other regulatory bodies.

[0045] The control module (130) receives an output from the refrigerant leak sensor (140) indicating that the amount of refrigerant exceeds a certain amount. When the output indicates that there is a leak (e.g., when the signal indicates that the amount of refrigerant is greater than a predetermined value or when the signal is in a first state), one or more corrective measures may be taken. For example, the control module (130) may turn on the blower (which blows air across the evaporator (108)) when the leak is present. Turning on the blower allows the leaked refrigerant to be dispersed. Additionally, the control module (130) may turn off the compressor (102) and keep the compressor (102) off until the leak is corrected. Additionally, the control module (130) may operate a lockout device to prevent ignition by one or more ignition devices within the building. Additionally, or alternatively, the control module (130) may close one or more isolation valves to isolate the refrigerant outside the building.

[0046] Additionally or alternatively, the control module (130) may generate one or more indicators when a leak is present. For example, the control module (130) may transmit the indicator to one or more external devices and generate one or more visual indicators (e.g., turning on one or more lights, displaying information on one or more displays) and / or one or more audible indicators, such as through one or more speakers.

[0047] The refrigerant leak sensor (140) may be, for example, a non-dispersive infrared (NDIR) refrigerant sensor, a thermally conductive refrigerant sensor, a quartz crystal microbalance (QCM) sensor, or other suitable types of refrigerant leak sensors. The NDIR sensor includes an infrared (IR) lamp that transmits light through a tube. A fan or blower may push or pull gas (e.g., air, or refrigerant in the case of a leak) through the tube. An optical sensor receives light from the IR lamp through the tube and measures the amount of refrigerant in the gas based on one or more properties of the light. The thermally conductive sensor includes conductive plates, and gas may be pushed or pulled between these conductive plates by a blower or fan. The blower or fan may be omitted in various implementations. The thermal conductivity varies depending on the amount of refrigerant. The thermally conductive sensor includes two temperature sensors (e.g., one in front and one behind the heating element). The thermally conductive sensor determines the temperature difference between the measurements of the two sensors. Given a known heating input from the heating element, the thermal conductivity sensor determines the amount of refrigerant based on the temperature difference. Different amounts of refrigerant result in different densities, which can cause different vibrations. The QCM sensor measures the amount of gaseous refrigerant based on the vibrations. Other examples of refrigerant leak sensors (140) include metal oxide refrigerant sensors, acoustic refrigerant sensors, quartz resonance (e.g., QCM) refrigerant sensors, and carbon nanotube refrigerant sensors. The metal oxide refrigerant sensor measures the resistance of a surface oxidizer heated by a hot plate. The resistance of the oxide layer may decrease when refrigerant is present. As the refrigerant dissipates, the resistance of the oxide layer may increase. The metal oxide refrigerant sensor can determine the amount of refrigerant based on the resistance.

[0048] To minimize power consumption of the refrigerant leak sensor (140), the control module (130) can toggle the on / off state of the refrigerant leak sensor (140) for the same predetermined period. That is, the control module (130) can turn the refrigerant leak sensor (140) on and off in a pulse manner, such as by directly connecting and disconnecting the power to the leak sensor (140). The control module (130) applies power to the refrigerant leak sensor (140) to turn the refrigerant leak sensor (140) on. The control module (130) cuts off the power to the refrigerant leak sensor (140) to turn the refrigerant leak sensor (140) off.

[0049] In various implementations, the refrigerant leak sensor (140) may be a digital sensor. In such implementations, the refrigerant leak sensor (140) may be configured to enter a standby (or reduced power / power saving) mode upon receiving a standby command from the control module (130). The control module (130) may toggle the refrigerant leak sensor (140) into an ON state and an OFF state by switching the refrigerant leak sensor (140) back and forth between a non-standby state and a standby state. As used herein, the term "ON state" may refer to operation in a non-standby mode, and as used herein, the term "OFF state" may refer to operation in a standby mode. Generally speaking, when the refrigerant leak sensor (140) is turned OFF, the control module (130) may reduce the power applied to the processor of the refrigerant leak sensor (140) (e.g., to 0% of the peak power). When the refrigerant leak sensor (140) is turned on, the control module (130) can supply power (e.g., up to 100% of the peak power) to the processor of the refrigerant leak sensor (140).

[0050] However, if the refrigerant leak sensor (140) is turned on and off in a pulsed manner, the refrigerant leak sensor (140) may be damaged. For example, the IR lamp may be damaged every time it is turned on.

[0051] The present application includes a control module (130) that controls power to a refrigerant leak sensor (140) to increase the lifespan of the refrigerant leak sensor (140) in relation to switching the refrigerant leak sensor (140) on and off in a pulsed manner. For example, the control module (130) can keep the refrigerant leak sensor (140) continuously on. This may increase power consumption but also increase the lifespan of the refrigerant sensor. The cost associated with the increased lifespan may be cost-advantageous compared to the cost of increased power consumption.

[0052] In various embodiments, the control module (130) may turn off the refrigerant leak sensor (140) only when one or more predetermined conditions are satisfied (and otherwise, may keep the refrigerant leak sensor (140) in the ON state). For example, the control module (130) may turn off the refrigerant leak sensor (140) when the blower blowing air through the evaporator (108) is in the ON state (when it is turned on) (and any possible leak will be mitigated when the blower is turned on). When the control module (130) turns the blower on by applying power to the blower (or transmitting a power application command), the control module (130) may infer that the blower is in the ON state. In various implementations, the control module (130) may turn on or leave the refrigerant leak sensor (140) when the blower is on, and obtain one or more measurements, such as verifying that any leak is being dissipated or reduced.

[0053] In various implementations, one or more measured parameters may be used to determine whether the blower is on, and the control module (130) may turn off the refrigerant leak sensor (140) when the blower is on. For example, the control module (130) may determine whether the blower is on based on atmospheric pressure, temperature, humidity of the air, current of the blower motor, voltage of the blower motor, power consumption of the blower motor, speed of the blower motor and / or flow rate of the air output by the blower, etc.

[0054] The control module (130) can vary the power applied to the refrigerant leak sensor (140) when switching the refrigerant leak sensor (140) from an off state to an on state or from an on state to an off state. For example, when the refrigerant leak sensor (140) is turned off, the control module (130) can rapidly decrease the power applied to the refrigerant leak sensor (140) linearly (ramp down). When the refrigerant leak sensor (140) is turned on, the control module (130) can rapidly increase the power applied to the refrigerant leak sensor (140) linearly (ramp up). Although an example of rapid linear increase / decrease (ramping) has been described, the control module (130) can change the applied power to other suitable patterns such as a sine wave, a triangle, a predetermined increment, etc.

[0055] FIG. 2 is a functional block diagram of an exemplary part of the cooling system of FIG. 1. When on, the blower (204) draws air from inside the building through one or more return air ducts. The blower (204) forces the air to pass through the evaporator (108). As the air passes through the evaporator (108), the evaporator (108) transfers heat to or from the air. The heated or cooled air flows from the evaporator (108) into the building through one or more air supply ducts.

[0056] In addition to the refrigerant leak sensor (140), one or more sensors may be implemented. For example, a motor current sensor (208) can measure the current flowing to the blower (204), more specifically, the electric motor of the blower (204). The control module (130) can determine that the blower (204) is in the ON state when the current is greater than a predetermined current (and can turn off the refrigerant leak sensor (140)).

[0057] Additionally or alternatively, a voltage sensor can measure the voltage applied to the electric motor of the blower (204). The control module (130) can determine that the blower (204) is in the ON state (and can turn off the refrigerant leak sensor (140)) when the voltage is greater than a predetermined voltage.

[0058] Additionally or alternatively, a power sensor can measure the power consumption of the electric motor of the blower (204). The control module (130) can determine that the blower (204) is in the ON state when the power consumption is greater than a predetermined power (and can turn off the refrigerant leak sensor (140)).

[0059] Additionally or alternatively, the speed sensor (212) can measure the rotational speed of the electric motor of the blower (204). The control module (130) can determine that the blower (204) is on (and the refrigerant leak sensor (140) is off) when the speed is greater than a predetermined speed.

[0060] Additionally or alternatively, one or more sensors may be implemented downstream of the evaporator (108). For example, a pressure sensor (216) may measure the pressure of the air downstream of the evaporator (108) (e.g., in the supply duct). The control module (130) may determine that the blower (204) is on (and may turn off the refrigerant leak sensor (140)) when the pressure is greater than a predetermined pressure (e.g., barometric pressure). The pressure may approach the barometric pressure when the blower (204) is off. The pressure may increase relative to the barometric pressure when the blower (204) is on.

[0061] Additionally or alternatively, a temperature sensor (220) can measure the air temperature downstream of the evaporator (108) (e.g., in the supply duct). The control module (130) can determine that the blower (204) is turned on (and the refrigerant leak sensor (140) can be turned off) if the temperature during heating is higher than a predetermined temperature (e.g., the set temperature of the thermostat) or is lower than a predetermined temperature during heating.

[0062] Additionally or alternatively, a relative humidity sensor (224) can measure the relative humidity (RH) of the air downstream of the evaporator (108) (e.g., in the supply duct). The control module (130) can determine that the blower (204) is on (and the refrigerant leak sensor (140) is off) if the relative humidity is greater or less than a predetermined relative humidity. Different predetermined relative humidityes may be used for the heating mode and the cooling mode.

[0063] Additionally or alternatively, an air flow rate (e.g., MAF (mass air flow rate)) sensor (228) can measure the air flow rate (e.g., mass flow rate) downstream of the evaporator (108) (e.g., in the supply duct). The control module (130) can determine that the blower (204) is turned on (and the refrigerant leak sensor (140) is turned off) when the air flow rate is greater than a predetermined air flow rate.

[0064] Although exemplary locations of the sensors are provided in FIG. 1, the sensors may be located in other appropriate locations. Additionally, one or more of the sensors in FIG. 2 may be omitted or duplicated.

[0065] FIG. 3 is a functional block diagram of an exemplary implementation of a control module (130). A compressor control module (304) controls the operation of a compressor (102). For example, the compressor control module (304) can turn on the compressor (102) in response to receiving a command from a thermostat (308). The thermostat (308) can generate a command, for example, when the air temperature inside a building is higher than the setpoint temperature (in the example of cooling) or lower than the setpoint temperature (in the example of heating). The compressor control module (304) can change the speed and / or capacity of the compressor (102) when the compressor (102) is turned on. The compressor control module (304) can turn off the compressor (102) when the thermostat (308) stops generating a command.

[0066] The fan control module (312) controls the operation of the condenser fan (316). The condenser fan (316) increases the airflow passing through the condenser (104) when the condenser fan (316) is in the ON state. For example, the fan control module (312) can turn on the condenser fan (316) in response to receiving a command from the thermostat (308). The fan control module (312) can turn off the condenser fan (316) when the thermostat (308) stops generating commands. In various embodiments, the fan control module (312) can turn on the condenser fan (316) before the compressor (102) is turned on, and keep the condenser fan (316) in the ON state for a certain period after the compressor (102) is turned off.

[0067] The blower control module (320) controls the operation of the blower (204). For example, the blower control module (320) may turn on the blower (204) in response to receiving a command from the thermostat (308). The blower control module (320) may turn off the blower (204) when the thermostat (308) stops generating a command. In various embodiments, the blower control module (320) may turn on the blower (204) before the compressor (102) turns on, and keep the blower (204) in the ON state for a predetermined period after the compressor (102) turns off.

[0068] The control modules discussed here turn the device on by supplying power to it. The control modules turn the device off by cutting off power to it.

[0069] The blower control module (320) can also turn on the blower (204) when a refrigerant leak is detected using the refrigerant leak sensor (140). For example, the leak module (324) can determine that there is a refrigerant leak in the cooling system if the amount of refrigerant measured outside the cooling system by the refrigerant leak sensor (140) is greater than a predetermined amount. The leak module (324) can determine that there is no refrigerant leak if the amount of refrigerant is less than the predetermined amount.

[0070] As described above, when a refrigerant leak is present in the cooling system, one or more other corrective measures may be taken. For example, the compressor control module (304) may turn off the compressor (102) when a refrigerant leak is present and keep the compressor (102) off for a predetermined period.

[0071] The power control module (328) controls the power being applied to the refrigerant leak sensor (140). That is, the power control module (328) turns the refrigerant leak sensor (140) on / off. In various implementations, the power control module (328) may keep the refrigerant leak sensor (140) continuously on. Keeping the refrigerant leak sensor (140) continuously on can increase the lifespan of the refrigerant leak sensor (140) compared to turning the refrigerant leak sensor (140) on and off.

[0072] Instead of keeping the refrigerant leak sensor (140) continuously in the ON state, the power control module (328) may turn the refrigerant leak sensor (140) ON and OFF. For example, requirements from one or more regulatory bodies (e.g., Underwriters Laboratories, UL) may require that the refrigerant leak sensor detect a leak within a predetermined maximum period of the leak's onset. However, the refrigerant leak sensor (140) may make reliable measurements within a predetermined measurement period after being turned ON. The predetermined measurement period is shorter than the predetermined maximum period of the leak's onset. Therefore, the power control module (328) may keep the refrigerant leak sensor (140) continuously ON during the predetermined measurement period within each predetermined maximum period. Otherwise, the power control module (328) may keep the refrigerant leak sensor (140) OFF. This allows the requirements of the regulatory body(s) to be satisfied while minimizing the period during which the refrigerant leak sensor (140) is in the ON state. The above-mentioned predetermined maximum period is set by a regulatory body and may be, for example, 10 seconds or other appropriate periods. The predetermined measurement period may be, for example, 2 seconds or other appropriate periods for the refrigerant leak sensor (140) to produce accurate measurements. The predetermined measurement period may be determined, for example, experimentally, or specified, for example, by the manufacturer of the refrigerant leak sensor (140).

[0073] Additionally or alternatively, the power control module (328) may turn off the refrigerant leak sensor (140) when the blower (204) is on (e.g., as indicated by a command from the thermostat (308). The power control module (328) may keep the refrigerant leak sensor (140) on otherwise (e.g., when the blower (204) is off).

[0074] In various implementations, the power control module (328) can determine whether the blower (204) is on (or verify whether the blower (204) is on) based on one or more measurements from one or more other sensors (332) mentioned above, and can turn off the refrigerant leak sensor (140) when the blower (204) is on. For example, the power control module (328) can turn off the refrigerant leak sensor (140) if the current flowing to the motor, measured using the current sensor (208), is greater than a predetermined current.

[0075] Additionally or alternatively, the power control module (328) may turn off the refrigerant leak sensor (140) when the voltage to the electric motor of the blower (204) is greater than a predetermined voltage. Additionally or alternatively, the power control module (328) may turn off the refrigerant leak sensor (140) when the speed of the electric motor of the blower (204), measured using the speed sensor (212), is greater than a predetermined speed.

[0076] Additionally or alternatively, the power control module (328) may turn off the refrigerant leak sensor (140) if the pressure measured using the pressure sensor (216) is greater than a predetermined pressure. Additionally or alternatively, the power control module (328) may turn off the refrigerant leak sensor (140) if the temperature measured by the temperature sensor (220) is higher than the set temperature during heating or lower than the predetermined temperature during cooling. Additionally or alternatively, the power control module (328) may turn off the refrigerant leak sensor (140) if the relative humidity measured by the relative humidity sensor (224) is greater than or less than a predetermined relative humidity selected for the current mode (e.g., heating mode or cooling mode). Additionally or alternatively, the power control module (328) may turn off the refrigerant leak sensor (140) if the air flow rate measured by the air flow sensor (228) is greater than a predetermined air flow rate. When the blower (204) is on, turning the refrigerant leak sensor (140) off can increase the lifespan of the refrigerant leak sensor (140).

[0077] The power control module (328) can supply power from an AC line to the refrigerant leak sensor (140). In various implementations, a conversion module (340) can convert the AC line into power suitable for supplying to the refrigerant leak sensor (140), and the power control module (328) can supply the power output by the conversion module to the refrigerant leak sensor (140). For example, the power control module (328) may include one or more switches. The power control module (328) can close the switch(s) to supply power to the refrigerant leak sensor (140). The power control module (328) can open the switch(s) to cut off power to the refrigerant leak sensor (140). In various implementations, the power control module (328) can control the power supply to the processor of the refrigerant leak sensor (140).

[0078] FIG. 4 is a flowchart illustrating an exemplary method of controlling the power supply of a refrigerant leak sensor (140). In various implementations, the power control module (328) may keep the refrigerant leak sensor (140) continuously on. Alternatively, in FIG. 404, the power control module (328) may obtain one or more current operating parameters such as a command for the blower (204), current for the blower (204), voltage applied to the blower (204), power consumption of the blower (204), speed of the blower (204), air pressure downstream of the evaporator (108), air temperature downstream of the evaporator (108), relative humidity of the air downstream of the evaporator (108), and air flow rate through the duct of the cooling system.

[0079] In 408, the power control module (328) determines whether the blower (204) is in the ON state. For example, the power control module (328) may determine that the blower (204) is in the ON state when a command to turn the blower (204) ON is received from the thermostat. Additionally or alternatively, the power control module (328) may determine that the blower (204) is in the ON state when the current to the motor measured using the current sensor (208) is greater than a predetermined current. Additionally or alternatively, the power control module (328) may determine that the blower (204) is in the ON state when the voltage to the electric motor of the blower (204) is greater than a predetermined voltage. Additionally or alternatively, the power control module (328) may determine that the blower (204) is in the ON state when the speed of the electric motor of the blower (204), measured using the speed sensor (212), is greater than a predetermined speed. Additionally or alternatively, the power control module (328) may determine that the blower (204) is in the ON state when the pressure, measured using the pressure sensor (216), is greater than a predetermined pressure. Additionally or alternatively, the power control module (328) may determine that the blower (204) is in the ON state when the temperature, measured by the temperature sensor (220), is higher than a predetermined temperature during heating or lower than a predetermined temperature during cooling. Additionally or alternatively, the power control module (328) may determine that the blower (204) is in the ON state when the relative humidity, measured by the relative humidity sensor (224), is greater than or less than a predetermined relative humidity. Additionally or alternatively, the power control module (328) can determine that the blower (204) is turned on when the air flow rate measured by the air flow sensor (228) is greater than a predetermined air flow rate.

[0080] When it is determined that the blower (204) is turned on at 408, the power control module (328) turns the refrigerant leak sensor (140) off at 412, and the control returns to 404. When it is determined that the blower (204) is not turned on at 408, the power control module (328) can turn the refrigerant leak sensor (140) on at 416, and the control can return to 404.

[0081] FIG. 5 is a flowchart illustrating an exemplary method of controlling the power supply of a refrigerant leak sensor (140). In various implementations, the power control module (328) may keep the refrigerant leak sensor (140) continuously on. Alternatively, in 504, the power control module (328) may reset the first timer and the second timer (Timer 1 and Timer 2). In 508, the power control module (328) turns the refrigerant leak sensor (140) on (or keeps it on). The first timer tracks the period during which the refrigerant leak sensor (140) was on. The second timer tracks the period since the refrigerant leak sensor (140) was last on.

[0082] At 512, the power control module (328) determines whether the predetermined measurement period of the refrigerant leak sensor (140) has elapsed since the refrigerant leak sensor (140) was last turned on. For example, the power control module (328) may determine whether the first timer is greater than the predetermined measurement period. If 512 is false, the power control module (328) increments the first timer and the second timer at 516, and the control returns to 508. In this way, the power control module (328) keeps the refrigerant leak sensor (140) turned on for the predetermined measurement period. If 512 is true, the control continues to 520.

[0083] At 520, the power control module (328) turns off the refrigerant leak sensor (140) (or keeps it off) and increments the second timer. At 524, the power control module (328) determines whether the predetermined maximum period has elapsed since the refrigerant leak sensor (140) was last turned on. For example, the power control module (328) may determine whether the second timer is greater than the predetermined maximum period. If 524 is false, control returns to 520. In this way, the power control module (328) keeps the refrigerant leak sensor (140) off for the remainder of the predetermined maximum period. If 524 is true, control returns to 504.

[0084] The foregoing description is by nature merely illustrative and is by no means intended to limit the disclosure, its application, or use. The broad teachings of this disclosure may be embodied in various forms. Accordingly, while this disclosure includes specific embodiments, the true scope of the disclosure should not be so limited as other modifications will become apparent from studying the drawings, the specification, and the following 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 has been described above as having specific features, any one or more of these features described for any embodiment of this disclosure may be embodied and / or combined with features of other embodiments, even if such combinations are not explicitly described. That is, the described embodiments are not mutually exclusive, and embodiments by permutations of one or more embodiments with other embodiments are within the scope of this disclosure.

[0085] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers) are described using various terms including “connected,” “connected,” “coupled,” “adjacent,” “next,” “on top,” “above,” “below,” “placed,” etc. Unless explicitly stated as “direct,” when a relationship between a first element and a second element is described in the disclosure above, the relationship may be a direct relationship in which no other intervening component exists between the first element and the second element, or an indirect relationship in which one or more intermediate elements (spatial or functional) exist between the first element and the second element. As used herein, the phrase “at least one of A, B, and C” should be interpreted to mean a logic (A OR B OR C) using a non-exclusive logical OR, and should not be interpreted to mean “at least one of A,” “at least one of B,” or “at least one of C.”

[0086] In the diagram, the direction of an arrow indicated by an arrowhead generally represents the flow of information of interest to the description (e.g., data or commands). For example, if Element A and Element B exchange various information but the information transmitted from Element A to Element B is relevant, the arrow may point from Element A to Element B. This unidirectional arrow does not imply that other information is not transmitted from Element B to Element A. Additionally, regarding the information transmitted from Element A to Element B, Element B may send a request for the information or an acknowledgment of receipt to Element A.

[0087] In this application, the terms “module” or “controller” may be replaced by the term “circuit”, including the definitions below. The term “module” may refer to an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit that executes code (shared, private, or group); a memory circuit that stores code executed by the processor circuit (shared, private, or group); other suitable hardware components that provide the described functions; or a combination of some or all of the above, such as a system-on-chip; or may refer to a part of or comprising these.

[0088] A module may include one or more interface circuits. In some examples, the interface circuit may include a wired or wireless interface connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functions of any given module of the present disclosure may be distributed among a number of modules connected through the interface circuit. For example, multiple modules may allow load balancing. In other examples, a server module (also referred to as a remote or cloud module) may perform some functions on behalf of a client module.

[0089] Some or all hardware functions of a module may be defined using a hardware description language such as IEEE Standard 1364-2005 (commonly referred to as "Verilog") and IEEE Standard 1076-2008 (commonly referred to as "VHDL"). Hardware description languages ​​may be used to manufacture and / or program hardware circuits. In some implementations, some or all functions of a module may be defined in a language such as IEEE 1666-2005 (commonly referred to as "SystemC"), which includes both the code and hardware description described below.

[0090] The term "code" as used above may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuit" includes a single processor circuit that executes part or all of the code of multiple modules. The term "group processor circuit" includes a processor circuit that executes part or all of the code of one or more modules together with additional processor circuits. References to "multiprocessor circuit" include multiprocessor circuits on individual dies, multiprocessor circuits on a single die, multicores of a single processor circuit, multithreads of a single processor circuit, or combinations of the above. The term "shared memory circuit" includes a single memory circuit that stores part or all of the code of multiple modules together with additional memory. The term "group memory circuit" includes a memory circuit that stores part or all of the code of one or more modules together with additional memory.

[0091] 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 (such as a carrier wave); therefore, the term computer-readable medium may be considered tangible and non-transient. Non-limiting examples of non-transient types of computer-readable medium include non-volatile memory circuits (e.g., flash memory circuits, erasable programmable read-only memory circuits, or mask read-only memory circuits), volatile memory circuits (e.g., static random access memory circuits or dynamic random access memory circuits), magnetic storage media (e.g., analog or digital magnetic tape or hard disk drives), and optical storage media (e.g., CDs, DVDs, or Blu-ray discs).

[0092] The apparatus and method described herein may be partially or fully implemented by a special-purpose computer created by configuring a general-purpose computer to execute one or more specific functions implemented in a computer program. The function blocks, flowchart components, and other elements described above serve as software specifications that can be converted into a computer program by the routine work of a skilled technician or programmer.

[0093] A computer program comprises processor-executable instructions stored on at least one non-transient, tangible computer-readable medium. A computer program may also include or rely on stored data. A computer program may include a Basic Input / Output System (BIOS) that interacts with the hardware of a special-purpose computer, a device driver that interacts with a specific device of the special-purpose computer, one or more operating systems, user applications, background services, and background applications.

[0094] A computer program may 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 from source code by a compiler; (iv) source code executed by an interpreter; (v) source code compiled and executed by a JIT compiler, etc. By way of example only, source code may be C, C++, C#, Objective C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th Revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic ® , Lua, MATLAB, SIMULINK, and Python ® It can be written using syntax from a language that includes.

Claims

Claim 1 A sensor control system comprising: a refrigerant leak sensor that measures the amount of refrigerant present in the air outside the heat exchanger of a cooling system when power is supplied; and a power control module; wherein the heat exchanger is located within a building that is heated, cooled, or heated and cooled by the cooling system, and the power control module: causes power to be cut off to the refrigerant leak sensor when a blower that moves air to pass through the heat exchanger is in the ON state; causes power to be supplied to the refrigerant leak sensor for a first predetermined period during each of the second predetermined periods when the blower is in the OFF state; causes power to be cut off to the refrigerant leak sensor for the remainder of each of the second predetermined periods; wherein the second predetermined period is longer than the first predetermined period, and the second predetermined period is a maximum period set by a regulatory authority during which refrigerant must be detected after the start of a leak, and the first predetermined period is a period during which the refrigerant leak sensor begins to generate reliable measurements after being turned ON. Claim 2 In claim 1, the power control module determines that the blower is in an ON state when the current to the electric motor of the blower is greater than a predetermined current, a sensor control system. Claim 3 In claim 1, the power control module determines that the blower is in an ON state when the voltage applied to the electric motor of the blower is greater than a predetermined voltage, a sensor control system. Claim 4 In claim 1, the power control module determines that the blower is in an ON state when the speed of the electric motor of the blower is greater than a predetermined speed, a sensor control system. Claim 5 In claim 1, the power control module determines that the blower is in an ON state when the downstream air pressure of the heat exchanger is greater than a predetermined pressure, a sensor control system. Claim 6 In claim 1, the sensor control system wherein the power control module determines that the blower is in an ON state when the downstream air temperature of the heat exchanger is lower than a predetermined temperature during cooling. Claim 7 In claim 1, the sensor control system wherein the power control module determines that the blower is in an ON state when the downstream air temperature of the heat exchanger is higher than a predetermined temperature during heating. Claim 8 In claim 1, the power control module determines that the blower is in an ON state when the downstream air humidity of the heat exchanger is greater than a predetermined humidity, a sensor control system. Claim 9 In claim 1, the power control module determines that the blower is in an ON state when the flow rate of air passing through the duct is greater than a predetermined flow rate, a sensor control system. Claim 10 A sensor control system according to claim 1, wherein the power control module determines that the blower is in the ON state when a command to turn the blower on is received. Claim 11 In paragraph 1, the sensor control system, wherein the refrigerant is classified as having weak flammability. Claim 12 In claim 1, the power control module is a sensor control system that supplies power to the refrigerant leak sensor when the blower is in an off state. Claim 13 A sensor control system comprising: a refrigerant leak sensor that measures the amount of refrigerant present in the air outside the heat exchanger of a cooling system when power is supplied; and a power control module; wherein the heat exchanger is located within a building that is heated, cooled, or heated and cooled by the cooling system, and the power control module: causes power to be supplied to the refrigerant leak sensor during a first predetermined period of each second predetermined period; causes power to be cut off to the refrigerant leak sensor during the remainder of each second predetermined period; wherein the second predetermined period is longer than the first predetermined period, and the second predetermined period is a maximum period set by a regulatory authority during which refrigerant must be detected after the start of a leak, and the first predetermined period is a period during which the refrigerant leak sensor begins to generate reliable measurements after being turned on. Claim 14 A sensor control method comprising: measuring the amount of refrigerant present in the air outside the heat exchanger of a cooling system by means of a refrigerant leak sensor; selectively cutting off power to the refrigerant leak sensor when a blower that moves air to pass through the heat exchanger is in the ON state; selectively cutting off power to the refrigerant leak sensor when the blower that moves air to pass through the heat exchanger is in the ON state; supplying power to the refrigerant leak sensor for a first predetermined period among each second predetermined period when the blower is in the OFF state; and cutting off power to the refrigerant leak sensor for the remainder of each second predetermined period; wherein the heat exchanger is located within a building that is heated, cooled, or heated and cooled by the cooling system, the second predetermined period is longer than the first predetermined period, the second predetermined period is a maximum period set by a regulatory body during which refrigerant must be detected after the start of a leak, and the first predetermined period is a period during which the refrigerant leak sensor begins to generate reliable measurements after being turned ON. Claim 15 In claim 14, the sensor control method further comprises determining that the blower is in an ON state when at least one of the following is true: when the current to the electric motor of the blower is greater than a predetermined current; when the voltage applied to the electric motor of the blower is greater than a predetermined voltage; when the speed of the electric motor of the blower is greater than a predetermined speed; when the downstream air pressure of the heat exchanger is greater than a predetermined pressure; when the downstream air temperature of the heat exchanger is lower than a predetermined temperature during cooling; when the downstream air temperature of the heat exchanger is higher than a predetermined temperature during heating; when the downstream air humidity of the heat exchanger is greater than a predetermined humidity; when the flow rate of air passing through the duct is greater than a predetermined flow rate; and when a command to turn the blower ON is received. Claim 16 In paragraph 14, the sensor control method wherein the refrigerant is classified as having weak flammability. Claim 17 In claim 14, the sensor control method further comprises supplying power to the refrigerant leak sensor when the blower is in an off state. Claim 18 In Clause 13, the above refrigerant is classified as having weak flammability, sensor control system. Claim 19 delete Claim 20 delete

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