Refrigerant leak sensor measurement conditioning system and method

Abstract

The refrigerant measurement and regulation system includes: a refrigerant sensor for a building, the refrigerant sensor being configured to measure the amount of refrigerant present in the air outside the building's refrigeration system; and a regulation module configured to: regulate the measured amount of refrigerant based on regulation to generate a regulation amount; and determine the regulation based on at least one of: air temperature; air pressure; relative humidity of the air; operating mode of the refrigeration system; changes in the refrigerant sensor measurement over time; and whether a fan blowing air through a heat exchanger of the refrigeration system located within the building is on.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Patent Application No. 17 / 077,479, filed October 22, 2020. The entire disclosure of the above application is incorporated herein by reference. Technical Field

[0003] This disclosure relates to refrigerant leak sensors, and more specifically, to systems and methods for controlling measurements of refrigerant leak sensors. Background Technology

[0004] The background description provided herein is for the purpose of presenting the general context of this disclosure. Within the scope described in this background section, the work of the currently named inventors and aspects that may not be described as prior art at the time of filing are neither explicitly nor implicitly acknowledged as prior art opposing this disclosure.

[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 are classified as A2L by ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers), meaning slightly flammable. UL (Underwriters Laboratories) standard 60335-2-40 and similar standards specify predetermined (M1) levels for A2L (or slightly flammable) refrigerants and indicate that refrigerant charge levels below the predetermined level do not require leak detection and mitigation. Summary of the Invention

[0007] In one aspect, a refrigerant measurement and regulation system includes: a refrigerant sensor for a building, the refrigerant sensor being configured to measure a dose of refrigerant present in the air outside the building's refrigeration system; and a regulation module configured to: regulate the measured dose of refrigerant based on regulation to generate a regulation amount; and determine the regulation based on at least one of: air temperature; air pressure; relative humidity of the air; operating mode of the refrigeration system; changes in the refrigerant sensor measurement over time; and whether a fan blowing air through a heat exchanger of the refrigeration system located within the building is activated.

[0008] Among other features, the leak module is configured to indicate the presence of a refrigerant leak based on regulation measurements.

[0009] Among other features, the regulation module is configured to determine regulation based on air temperature.

[0010] Among other features, the regulation module is configured to determine regulation based on changes in air temperature.

[0011] Among other features, the regulation module is configured to determine regulation based on air pressure.

[0012] Among other features, the regulation module is configured to determine regulation based on changes in air pressure.

[0013] Among other features, the adjustment module is configured to determine adjustment based on relative humidity.

[0014] Among other features, the adjustment module is configured to determine adjustment based on changes in relative humidity.

[0015] Among other features, the adjustment module is configured to set the adjustment based on the cooling dose measured when the operating mode is in heating mode for a predetermined period of time.

[0016] Among other features, the regulation module is configured to set the regulation based on the amount of refrigerant measured after the refrigerant has been pumped out of the building.

[0017] Among other features, the regulation module is configured to set regulation based on the amount of refrigerant measured when the operating mode is switched from cooling mode to heating mode and refrigerant has been pumped out of the building.

[0018] Among other features, the regulation module is configured to set regulation based on the amount of refrigerant measured when the fan has been on for at least a predetermined period of time.

[0019] Among other features, the adjustment module is configured to: further adjust the refrigerant dose based on the second adjustment to generate an adjustment measurement; and determine the second adjustment based on the change in refrigerant dose over time as measured by the refrigerant sensor.

[0020] Among other features, the adjustment module is configured to set the adjustment amount based on one of (a) the measured refrigerant dose plus the adjustment and (b) the measured refrigerant dose minus the adjustment.

[0021] Among other features, the adjustment module is configured to set the adjustment amount based on the measured refrigerant dose multiplied by the adjustment.

[0022] Among other features, the adjustment module is configured to adjust the amount based on at least two adjustments, which are determined based on at least two of the following: air temperature; air pressure; relative humidity of the air; operating mode of the refrigeration system; changes in the refrigerant sensor measurement over time; and whether the fan blowing air through the heat exchanger of the refrigeration system located within the building is on.

[0023] Among other features, the adjustment module is configured to adjust the amount based on adjustments determined based on each of the following: air temperature; air pressure; relative humidity of the air; operating mode of the refrigeration system; changes in refrigerant sensor measurements over time; and whether the fan blowing air through the heat exchanger of the refrigeration system located within the building is on.

[0024] Among other features: the adjustment module is configured to adjust the measured refrigerant dosage based on the change in the refrigerant sensor measurement over time; and the refrigerant measurement adjustment system also includes a life-end module configured to indicate that the refrigerant sensor is at the end of its lifespan when the magnitude of the change is greater than a predetermined value.

[0025] Among other features: the adjustment module is configured to adjust the measured refrigerant dose based on the change in the refrigerant sensor measurement over time; and the refrigerant measurement adjustment system also includes a life-end module configured to indicate that the refrigerant sensor is at the end of its lifespan when the magnitude of the change increases over at least a predetermined number of consecutive instances.

[0026] In one feature, the refrigerant measurement and regulation method includes: measuring the amount of refrigerant present in the air outside the building's refrigeration system using a refrigerant sensor for the building; regulating the measured amount of refrigerant based on regulation to produce a regulation amount; determining the regulation based on at least one of: air temperature; air pressure; relative humidity of the air; operating mode of the refrigeration system; changes in the refrigerant sensor measurement over time; and whether a fan blowing air through a heat exchanger of the refrigeration system located inside the building is turned on.

[0027] Further applicability of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0028] This disclosure will be more fully understood in light of the specific embodiments and accompanying drawings, in which:

[0029] Figure 1 This is a functional block diagram of an example refrigeration system;

[0030] Figure 2 yes Figure 1 Functional block diagram of an example section of a refrigeration system;

[0031] Figure 3 This is a functional block diagram of an example implementation of the control module;

[0032] Figure 4 This is a functional block diagram of the example adjustment module;

[0033] Figure 5 This is a flowchart depicting an example method for adjusting the measurements of a refrigerant leak sensor and performing leak detection and remediation; and

[0034] Figure 6 This is a flowchart depicting an example method for determining drift regulation and diagnosing end-of-life conditions.

[0035] In the accompanying drawings, reference numerals may be reused to identify similar and / or identical elements. Detailed Implementation

[0036] Some refrigerants used in refrigeration systems can be classified as mildly flammable (e.g., A2L refrigerant). Refrigeration systems using mildly flammable refrigerants may include a refrigerant leak sensor configured to measure the amount of refrigerant present in the air outside the refrigeration system within the building it serves. This amount of refrigerant corresponds to the amount of refrigerant leaking from the refrigeration system.

[0037] As refrigerant leak sensors age, their measurements may naturally change over time. For example, the measurements may drift over time. The measurements may also vary due to one or more operating conditions, such as the operating mode of the refrigeration system, whether the fan is on, and / or the relative humidity, temperature, or air pressure at the refrigerant leak sensor location.

[0038] In view of the above, this application relates to adjusting the measurement of a refrigerant leak sensor. This improves the accuracy of the measurement and extends the service life of the refrigerant leak sensor.

[0039] Figure 1 This is a functional block diagram of an example refrigeration system 100 including 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 dryer. Furthermore, this disclosure applies to other types of refrigeration systems, including but not limited to heating, ventilation, and air conditioning (HVAC) systems, heat pump systems, refrigeration systems, and cooling systems. For example, the refrigeration system 100 may include a reversing valve (not shown) configured to reverse the flow direction of refrigerant in a heat pump system.

[0040] Compressor 102 receives refrigerant in vapor form and compresses the refrigerant. Compressor 102 supplies pressurized refrigerant in vapor form to condenser 104. Compressor 102 includes a motor that drives a pump. By way of example only, the pump of compressor 102 may include a scroll compressor and / or a reciprocating compressor.

[0041] All or part of the pressurized refrigerant is converted into a liquid form within condenser 104. Condenser 104 transfers heat away from the refrigerant, thereby cooling it. When the refrigerant vapor is cooled to a temperature below its saturation temperature, the refrigerant transforms into a liquid (or liquefied) refrigerant. Condenser 104 may include an electric fan, which increases the rate of heat transfer away from the refrigerant.

[0042] The condenser 104 supplies refrigerant to the evaporator 108 via the expansion valve 106. The expansion valve 106 controls the flow rate of refrigerant supplied to the evaporator 108. The expansion valve 106 may include a thermostatic expansion valve, or it may be electronically controlled, for example, by a control module 130. The pressure drop caused by the expansion valve 106 can cause a portion of the liquefied refrigerant to convert back into vapor form. In this way, the evaporator 108 can receive a mixture of refrigerant vapor and liquefied refrigerant.

[0043] The refrigerant absorbs heat in the evaporator 108. When heated to a temperature greater than the refrigerant's saturation temperature, the liquid refrigerant transforms into a vapor form. The evaporator 108 may include an electric fan, which increases the rate of heat transfer to the refrigerant.

[0044] Utility 120 supplies power to the cooling system 100. By way of example only, utility 120 can provide approximately 230 volts (RMS). RMS The utility 120 provides single-phase alternating current (AC) power. In other implementations, the utility 120 may provide approximately 400V at a line frequency of, for example, 50 Hz or 60 Hz. RMS 480 V RMS Or 600 V RMS Three-phase AC power. The three-phase AC power is rated at 600V. RMS At that time, the actual usable voltage of electricity can be 575V. RMS .

[0045] The utility 120 can supply AC power to the control module 130 via an AC line comprising two or more conductors. AC power can also be supplied to the drive 132 via the AC line. The control module 130 controls the refrigeration system 100. By way of example only, the control module 130 can control the refrigeration system 100 based on parameters measured by various sensors (not shown) and / or user input. 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 via a serial data bus or other suitable data bus.

[0046] User interface 134 provides user input to control module 130. User interface 134 may additionally or alternatively provide user input directly to driver 132. User input may include, for example, desired temperature, requests to operate the fan (e.g., requests to continuously operate the evaporator fan), and / or other suitable input. User interface 134 may take the form of a thermostat, and some or all of the functions of the control module (including, for example, actuating the heat source) may be integrated into the thermostat.

[0047] 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 actuation of the reversing valve.

[0048] The drive 132 can control the compressor 102 based on commands from the control module 130. By way of example only, the control module 130 can instruct the drive 132 to run the motor of the compressor 102 at a certain speed, or to run the compressor 102 at a certain capacity. In various implementations, the drive 132 can also control the condenser fan.

[0049] Evaporator 108 can be located inside a building served by a refrigeration system. Condenser 104 can be located outside the building. In a heat pump system, the functions of evaporator 108 and condenser 104 are switched depending on whether heating or cooling is being performed inside the building. When cooling is being performed, condenser 104 and evaporator 108 perform as described above. When heating is being performed, the refrigerant flow is reversed, and condenser 104 and evaporator 108 operate in reverse. Condenser 104 and evaporator 108 can therefore be more generally referred to as heat exchangers.

[0050] A refrigerant leak sensor 140 is located inside a building and measures the amount (e.g., concentration) of refrigerant in the air (outside the refrigeration system) present at the location of the refrigerant leak sensor. The refrigerant leak sensor 140 may be located, for example, near an evaporator 108, downstream of a fan that blows air across the evaporator 108 and into the building through ducts. The refrigerant leak sensor 140 may also be located downstream of the evaporator 108.

[0051] 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 the signal to a first state when the amount is greater than a predetermined amount, and set the signal to a second state when the amount is less than a predetermined amount. The predetermined amount can be, for example, 25% of the lower flammability level of the refrigerant or another suitable value. In various implementations, the refrigerant is classified as slightly flammable according to one or more criteria. By way of example only, as mentioned above, the refrigerant can be classified as A2L refrigerant or more generally slightly flammable. The classification can be, for example, according to ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers) standards, UL (Underwriters Laboratories) 60335-2-40 standards, or can adopt another standard according to ASHRAE, UL, or another regulatory agency.

[0052] The control module 130 receives the output of the refrigerant leak sensor 140 and determines whether a refrigerant leak exists based on the output. For example, when the output is in a first state or when the amount is greater than a predetermined amount, the control module 130 can determine that a leak exists. If the amount is less than the predetermined amount or the output is in a second state, the control module 130 can determine that no leak exists.

[0053] When a refrigerant leak is detected (e.g., a signal indicating a value greater than a predetermined value or a signal in a first state), one or more remedial measures can be taken. For example, when a leak is detected, control module 130 can connect a fan (to blow air across evaporator 108). Connecting the fan can disperse the leaking refrigerant. Additionally, control module 130 can shut down compressor 102 and remain shut down until the leak is remedied (e.g., for a predetermined period of time). Furthermore, control module 130 can actuate a locking device to prevent ignition of one or more ignition devices within the building. Additionally or alternatively, control module 130 can close one or more isolation valves to isolate the refrigerant outside the building. In various implementations, a first isolation valve can be directly implemented between condenser 104 and expansion valve 106. When a leak is detected, control module 130 can close the first isolation valve. A second isolation valve can be directly implemented between evaporator 108 and compressor 102. When compressor 102 is turned on and the first isolation valve is closed to pump refrigerant out of the building, control module 130 can keep the second isolation valve open. After a predetermined period of operation with compressor 102 running with the first isolation valve closed, control module 130 can close the second isolation valve.

[0054] Alternatively or additionally, in the presence of leakage, the control module 130 may generate one or more indicators. For example, the control module 130 may send indicators to one or more external devices, generate one or more visual indicators (e.g., turn on one or more lights, display information on one or more displays, etc.), and / or generate one or more audible indicators, for example, via one or more speakers.

[0055] The refrigerant leak sensor 140 can be, for example, a nondispersive infrared (NDIR) refrigerant sensor, a thermal conductivity refrigerant sensor, a quartz crystal microbalance (QCM) sensor, or other suitable type of refrigerant leak sensor. The NDIR sensor includes an infrared (IR) lamp that transmits light through a conduit. A fan or blower can push or pull a gas (e.g., air, and if a leak is present, refrigerant) through the conduit. An optical sensor receives light from the IR lamp through the conduit and measures the amount of refrigerant in the gas based on one or more properties of the light. The thermal conductivity sensor includes conductive plates that can be pushed or pulled between by a fan or blower. The fan or blower may be omitted in various implementations. Different amounts of refrigerant have different thermal conductivities. The thermal conductivity sensor includes two temperature sensors (e.g., one before the heating element and one after the heating element). The thermal conductivity sensor determines the temperature difference between the measurements from 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 have different densities and can therefore cause different vibrations. QCM sensors measure the amount of refrigerant in a gas based on vibration. Other examples of the refrigerant leak sensor 140 include metal oxide refrigerant sensors, acoustic refrigerant sensors, quartz resonance (e.g., QCM) refrigerant sensors, and carbon nanotube refrigerant sensors. Metal oxide refrigerant sensors measure the resistance of a surface oxide layer heated by a hot plate. In the presence of refrigerant, the resistance of the oxide layer may decrease. As the refrigerant dissipates, the resistance of the oxide layer may increase. Metal oxide refrigerant sensors can determine the amount of refrigerant based on this resistance.

[0056] The amount of refrigerant measured by the refrigerant leak sensor 140 may naturally deviate from the actual amount of refrigerant over time. For example, the measured amount of refrigerant may drift over time. One or more environmental conditions (e.g., temperature, pressure, humidity) may cause inaccuracies in the amount of refrigerant measured by the refrigerant leak sensor 140. Fan operation may also cause inaccuracies in the measured amount of refrigerant. The response of the refrigerant leak sensor 140 to changes in one or more environmental conditions (e.g., temperature, pressure, humidity) may also slow down or accelerate over time.

[0057] This application relates to adjusting the refrigerant charge measured by refrigerant leak sensor 140 to take into account the above situations. For example, an adjustment for drift can be determined and used to adjust the measured refrigerant charge. Alternatively, one or more adjustments can be determined based on one or more environmental conditions and used to adjust the measured refrigerant charge. Alternatively, an adjustment for when environmental conditions change can be determined and used to adjust the measured refrigerant charge. Alternatively, an adjustment for when the fan is turned on can be determined and used to adjust the measured refrigerant charge. Alternatively, an adjustment can be determined based on the difference between measurements during heating and cooling mode operation and used to adjust the measured refrigerant charge.

[0058] Figure 2 yes Figure 1 The diagram shows a functional block diagram of an example portion of the refrigeration system. When switched on, fan 204 draws air from inside the building through one or more return air ducts. Fan 204 forces the air through evaporator 108. As the air passes through evaporator 108, evaporator 108 transfers heat to or from the air. The heated or cooled air flows from evaporator 108 into the building through one or more supply air ducts.

[0059] In addition to the refrigerant leak sensor 140, one or more sensors can be implemented. For example, the motor current sensor 208 can measure the current to the fan 204, and more specifically, the current to the motor of the fan 204. When the current is greater than a predetermined current, the control module 130 can determine that the fan 204 is turned on (and turn off the refrigerant leak sensor 140).

[0060] Alternatively or additionally, a voltage sensor can measure the voltage applied to the motor of fan 204. When the voltage is greater than a predetermined voltage, control module 130 can determine that fan 204 is turned on (and turn off refrigerant leak sensor 140).

[0061] Alternatively or additionally, a power sensor can measure the power consumption of the motor of fan 204. When the power consumption exceeds a predetermined power, control module 130 can determine that fan 204 is turned on (and turn off refrigerant leak sensor 140).

[0062] Alternatively or additionally, speed sensor 212 can measure the rotational speed of the motor of fan 204. When the speed is greater than a predetermined speed, control module 130 can determine that fan 204 is turned on (and turn off refrigerant leak sensor 140).

[0063] Alternatively or additionally, one or more sensors may be implemented downstream of the evaporator 108. For example, pressure sensor 216 may measure the air pressure downstream of the evaporator 108 (e.g., in a supply air duct). When the pressure is greater than a predetermined pressure (e.g., atmospheric pressure), control module 130 may determine that fan 204 is turned on (and refrigerant leak sensor 140 is turned off). When fan 204 is off, the pressure may be close to atmospheric pressure. When fan 204 is on, the pressure may increase relative to atmospheric pressure.

[0064] Alternatively or additionally, temperature sensor 220 may measure the air temperature downstream of evaporator 108 (e.g., in the air supply duct). Control module 130 may determine that fan 204 is turned on (and refrigerant leak sensor 140 is turned off) when the temperature is higher than a predetermined temperature during heating (e.g., the setpoint pressure of a thermostat) or lower than a predetermined temperature during cooling. The temperature measured by temperature sensor 220 may be the ambient temperature when fan 204 is off.

[0065] Alternatively or additionally, the relative humidity sensor 224 can measure the relative humidity (RH) of the air downstream of the evaporator 108 (e.g., in a supply air duct). When the relative humidity is greater than or less than a predetermined relative humidity, the control module 130 can determine that the fan 204 is turned on (and the refrigerant leak sensor 140 is turned off). Different predetermined relative humidities can be used for heating and cooling modes. The relative humidity measured by the relative humidity sensor 224 can be the ambient relative humidity when the fan 204 is off.

[0066] Alternatively or additionally, airflow (e.g., mass airflow (MAF)) sensor 228 can measure the flow rate (e.g., mass flow rate) of air downstream of evaporator 108 (e.g., in a supply air duct). When the airflow exceeds a predetermined airflow, control module 130 can determine that fan 204 is turned on (and turn off refrigerant leak sensor 140).

[0067] Although Figure 2 Example sensor locations are provided, but sensors can be placed in other suitable locations. Furthermore, these can be omitted or repeated. Figure 2 One or more sensors.

[0068] Figure 3This is a functional block diagram of an example implementation of control module 130. Compressor control module 304 controls the operation of compressor 102. For example, compressor control module 304 can turn on compressor 102 in response to a command (e.g., a cooling mode command) received from thermostat 308. For example, thermostat 308 can generate a command when the air temperature inside the building is greater than a setpoint temperature (in the cooling example) or less than a setpoint temperature (in the heating example). When compressor 102 is turned on, compressor control module 304 can change the speed and / or capacity of compressor 102. When thermostat 308 stops generating commands, compressor control module 304 can turn off compressor 102.

[0069] The fan control module 312 controls the operation of the condenser fan 316. When the condenser fan 316 is turned on, it increases the airflow through the condenser 104. For example, the fan control module 312 can turn on the condenser fan 316 in response to a command received from the thermostat 308. When the thermostat 308 stops generating commands, the fan control module 312 can turn off the condenser fan 316. In various implementations, 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 on for a predetermined period of time after the compressor 102 is turned off.

[0070] The fan control module 320 controls the operation of the fan 204. For example, the fan control module 320 can turn on the fan 204 in response to a command received from the thermostat 308. The fan control module 320 can also turn on the fan 204 in response to a heating command received from the thermostat 308. The fan control module 320 can also turn on the fan 204 in response to a command (fan on command) received from the thermostat 308. When the thermostat 308 does not generate any command, the fan control module 320 can turn off the fan 204. In various implementations, the fan control module 320 can turn on the fan 204 before the compressor 102 is turned on and keep the fan 204 on for a predetermined period of time after the compressor 102 is turned off.

[0071] The control module discussed in this article connects the device by supplying power to it. The control module shuts down the device by disconnecting the power supply.

[0072] When a refrigerant leak is detected using the refrigerant leak sensor 140, the fan control module 320 can also be connected to the fan 204. For example, when the amount of refrigerant measured outside the refrigeration system by the refrigerant leak sensor 140 is greater than a predetermined amount, the leak module 324 can determine that there is a refrigerant leak in the refrigeration system. When the amount is less than the predetermined amount, the leak module 324 can determine that there is no refrigerant leak.

[0073] As described above, when a refrigerant leak occurs in the refrigeration system, one or more other remedial measures can be taken. For example, when a refrigerant leak occurs, the compressor control module 304 can shut down the compressor 102 and keep it off for a predetermined period of time. Alternatively, one or more isolation valves can be closed, for example, to pump the refrigerant out of the building and trap it outside the building.

[0074] As described above, the refrigerant charge measured by the refrigerant leak sensor 140 may differ from the actual refrigerant charge present at the refrigerant leak sensor 140. The adjustment module 328 adjusts the refrigerant charge measured by the refrigerant leak sensor before, for example, the (adjusted) refrigerant charge is used by the leak module 324. The adjustment module 328 may determine one or more adjustments based on measurements from one or more other sensors 332, such as temperature sensor 220, relative humidity sensor 224, pressure sensor 216, and / or one or more other types of sensors. Although the adjustment module 328 is shown as being implemented within the control module 130, the adjustment module 328 may be implemented within the refrigerant leak sensor 140, or a portion of the functionality of the adjustment module 328 may be implemented within the refrigerant leak sensor 140, and a portion (e.g., the remainder) of the functionality of the adjustment module 328 may be implemented within the control module 130.

[0075] Figure 4 This is a functional block diagram of an example implementation of the regulating module 328. The first regulating module 404 receives measurements from the refrigerant leak sensor 140. The measurements include the amount of refrigerant measured by the refrigerant leak sensor 140.

[0076] The first adjustment module 404 adjusts the measurement based on the drift adjustment to generate a first adjustment measurement. For example, the first adjustment module 404 may set the first adjustment measurement based on or equal to the sum (addition) or product (multiplication) of the drift adjustment and the measurement.

[0077] The drift module 408 determines drift adjustment based on the difference between two measurements taken at two different times. For example, the drift module 408 may set the drift adjustment based on or equal to a first measurement from a first time minus a second measurement from a second time. The first measurement may be stored, for example, in the refrigerant leak sensor 140, and may be a first measurement received from the refrigerant leak sensor 140 by the first adjustment module 404, a measurement from a previous time (relative to the current time), or another suitable measurement. The second measurement may be a measurement received after the first measurement, the current measurement, or another suitable measurement.

[0078] The second adjustment module 412 receives the first adjustment measurement (the measured cooling dose of the first adjustment). The second adjustment module 412 adjusts the first adjustment measurement based on the environmental adjustment to generate the second adjustment measurement. For example, the second adjustment module 412 may set the second adjustment measurement based on or equal to the sum (addition) of the environmental adjustment and the first adjustment measurement or the product (multiplication) of the environmental adjustment and the first adjustment measurement.

[0079] The environmental module 416 determines environmental regulation based on environmental parameters such as ambient temperature, ambient pressure, or ambient relative humidity. Ambient temperature can be measured by temperature sensor 220 when fan 204 is off. Ambient pressure can be measured by pressure sensor 216 when fan 204 is off. Ambient relative humidity can be measured by relative humidity sensor 224 when fan 204 is off. The environmental module 416 can determine environmental regulation, for example, using one of the lookup tables and equations that associate the values ​​of environmental parameters with environmental regulation.

[0080] In various implementations, the environment module 416 can determine multiple environmental controls, such as a first environmental control based on ambient temperature, a second environmental control based on ambient pressure, and a third environmental control based on ambient relative humidity. In such an implementation, the second control module 412 can adjust the first control measurement based on each of the environmental controls, for example, by adding or multiplying each environmental control.

[0081] The environmental module 416 may also include inputs that signal the fan power status and mode (e.g., heating, cooling, off). This allows the environmental module 416 to anticipate / predict what changes it will see under environmental conditions. For example, if the thermostat is in cooling mode and the fan is on, the environmental module 416 may expect to see a decrease in temperature, an increase in humidity, and an increase in atmospheric pressure. If these expected changes are reflected in all but one of the sensors, it may indicate that the sensor is malfunctioning or nearing the end of its lifespan.

[0082] The third adjustment module 420 receives the second adjustment measurement (the measured cooling dose of the second adjustment). The third adjustment module 420 adjusts the second adjustment measurement based on the change adjustment to generate the third adjustment measurement. For example, the third adjustment module 420 may set the third adjustment measurement based on or equal to the sum (addition) of the change adjustment and the second adjustment measurement or the product (multiplication) of the change adjustment and the second adjustment measurement.

[0083] Variation module 424 determines variation regulation based on measured changes that occur in response to changes in parameters (e.g., temperature, pressure, or relative humidity). Temperature can be measured by temperature sensor 220. Pressure can be measured by pressure sensor 216. Relative humidity can be measured by relative humidity sensor 224. Variation module 424 can determine variation regulation, for example, using one of a lookup table and equation that associates measured changes in parameters with variation regulation.

[0084] In various implementations, the variation module 424 can determine multiple variation adjustments, such as a first variation adjustment based on temperature changes, a second variation adjustment based on pressure changes, and a third variation adjustment based on relative humidity changes. In such an implementation, the third adjustment module 420 can adjust the second adjustment measurement based on each of the variation adjustments, for example, by adding or multiplying each variation adjustment.

[0085] In various implementations, the variation module 424 can determine the variation adjustment based on the final adjustment measurement output by the adjustment module 328. However, the variation module 424 can also disable each adjustment in the adjustment to determine the variation adjustment.

[0086] The fourth adjustment module 428 receives the third adjustment measurement (the measured refrigerant charge of the third adjustment). The fourth adjustment module 428 adjusts the third adjustment measurement based on the fan adjustment to generate the fourth adjustment measurement. For example, the fourth adjustment module 428 may set the fourth adjustment measurement based on or equal to the sum (addition) of the fan adjustment and the third adjustment measurement (e.g., in an example where the fan adjustment is negative), or the product (multiplication) of the fan adjustment and the third adjustment measurement (e.g., in an example where the fan adjustment is positive), or the difference (subtraction) between the third adjustment measurement and the fan adjustment (e.g., in an example where the fan adjustment is positive).

[0087] The fan regulation module 432 determines fan regulation based on whether the fan 204 is on. When the fan 204 is on for at least a predetermined period of time, any refrigerant leakage should be mitigated, and therefore the measurement from the refrigerant leak sensor 140 should be zero. However, as the refrigerant leak sensor 140 ages, the measurement may increase or decrease. In some implementations, the measurement may become negative. Therefore, when the fan 204 switches off after being on for at least a predetermined period of time (making the measurement zero), the fan regulation module 432 can thus set the fan regulation based on or equal to the measurement from the refrigerant leak sensor 140 (a positive value). The fan regulation module 432 can also make the fan regulation negative (e.g., -measurement) to produce a negative value.

[0088] The fifth adjustment module 436 receives the fourth adjustment measurement (the measured refrigerant charge of the fourth adjustment). The fifth adjustment module 436 adjusts the fourth adjustment measurement based on the mode adjustment to produce the (final) adjustment measurement. For example, the fifth adjustment module 436 may set the adjustment measurement based on or equal to the sum (addition) of the mode adjustment and the fourth adjustment measurement (e.g., in an example where the mode adjustment is negative), or the product (multiplication) of the mode adjustment and the fourth adjustment measurement (e.g., in an example where the mode adjustment is positive), or the difference (subtraction between the mode adjustment and the fourth adjustment measurement (e.g., in an example where the mode adjustment is positive)). The leakage module 324 determines whether a refrigerant leak exists based on the adjustment measurement output by the adjustment module 328, as described above.

[0089] The mode module 438 determines the mode adjustment based on the current operating mode of the refrigeration system. The thermostat 308 sets the operating mode to one of heating mode, cooling mode, or off. When the refrigeration system is off or switched to heating mode, pumping can be performed to pump refrigerant out of the indoor section of the refrigeration system. Therefore, even if a refrigerant leak exists, the measurement of the refrigerant leak sensor 140 should be zero. When the mode is switched to heating mode or in other cases when pumping has been performed, the mode module 438 can therefore set the mode adjustment based on or equal to the measurement of the refrigerant leak sensor 140. If the measurement has a negative drift, the mode module 438 can make the mode adjustment negative (e.g., -measurement) to produce a negative or positive value.

[0090] Although Figure 4 The example order of applying the adjustments is provided, but adjustments can be applied in a different order. Furthermore, one or more adjustments discussed above can be omitted.

[0091] Return to reference Figure 3 The end-of-life module 440 can indicate whether the refrigerant leak sensor 140 is at or near the end of its service life. When the refrigerant leak sensor 140 is at or near the end of its service life, the measurements of the refrigerant leak sensor 140 may have less accuracy than a predetermined value. When the refrigerant leak sensor 140 is at or near the end of its service life, the refrigerant leak sensor 140 should be replaced.

[0092] When a measured change in response to a change in relative humidity is greater than or less than a predetermined expected value limit associated with the relative humidity change, the lifespan termination module 440 can determine whether the refrigerant leak sensor 140 is at or nearing the end of its service life. The aforementioned adjustment can help increase the service life of the refrigerant leak sensor 140. Additionally or alternatively, when a measured change in response to a change in temperature is greater than or less than a predetermined expected value limit associated with the temperature change, the lifespan termination module 440 can determine whether the refrigerant leak sensor 140 is at or nearing the end of its service life. When a measured change in response to a change in pressure is less than a predetermined expected value associated with the pressure change, the lifespan termination module 440 can determine whether the refrigerant leak sensor 140 is at or nearing the end of its service life. When the mode adjustment (determined based on the difference between the first and second measurements) is greater than or less than a predetermined value, the lifespan termination module 440 can additionally determine whether the refrigerant leak sensor 140 is at or nearing the end of its service life.

[0093] When one or more adjustments (e.g., fan adjustment, drift adjustment, mode adjustment, etc.) are greater than or less than a predetermined value, the life-end module 440 may additionally or alternatively determine that the refrigerant leak sensor 140 is at or near the end of its lifespan.

[0094] When the refrigerant leak sensor 140 is at or near the end of its service life, the life-end module 440 may take one or more remedial measures. For example, when the refrigerant leak sensor 140 is at or near the end of its service life, the life-end module 440 may emit light, store a predetermined code in memory, send a message to one or more computing devices via a network, or perform one or more other remedial measures.

[0095] Figure 5 This is a flowchart depicting an example method for regulating the measurements of the refrigerant leak sensor 140 and performing leak detection and remediation. Control begins at 504, where the regulation module 328 receives measurements from the refrigerant leak sensor 140. As described above, the regulation module 328 also acquires or determines regulation.

[0096] At 508, the first adjustment module 404 can determine a first adjustment measurement based on the measurement (from 504) and drift adjustment. At 512, the second adjustment module 412 determines a second adjustment measurement based on the first adjustment measurement and environmental adjustment. At 516, the third adjustment module 420 determines a third adjustment measurement based on the second adjustment measurement and variation adjustment. At 520, the fourth adjustment module determines a fourth adjustment measurement based on the third adjustment measurement and fan adjustment. At 524, the fifth adjustment module 436 determines an adjustment measurement based on the fourth adjustment measurement and mode adjustment. As mentioned above, one or more adjustments can be omitted, and different adjustment sequences can be used.

[0097] At 528, the leakage module 324 determines whether the adjusted measurement is greater than a predetermined amount of refrigerant. If 528 is false, at 532 the leakage module 324 indicates that there is no refrigerant leak, and control returns to 504 for the next measurement. If 528 is true, control continues to 536.

[0098] At point 536, leak module 324 indicates the presence of a refrigerant leak. At point 540, in response to the diagnosis of a refrigerant leak, one or more remedial measures are performed. For example, fan control module 320 may engage fan 204 for a predetermined period to dissipate any leaked refrigerant. Compressor control module 304 may also shut down compressor 102 for a predetermined period. Before shutting down the compressor, compressor control module 304 may engage compressor 102 to pump refrigerant out of the building. One or more valves may be actuated to trap refrigerant outside the building.

[0099] Figure 6 This is a flowchart depicting an example method for determining drift adjustment and whether the refrigerant leak sensor 140 is at or nearing the end of its service life. Control begins at 601, where the adjustment module 328 determines whether an indication has been generated that the refrigerant leak sensor 140 is at or nearing the end of its service life. If 601 is true, control moves to 602. If 601 is false, control continues to 604. At 602, the adjustment module 328 determines whether a predetermined period has elapsed since the indication was generated. If 602 is false, leak mitigation is performed at 603. For example, the fan control module 320 may be connected to the fan 204. Furthermore, the control module 130 may lock one or more locking devices to prevent ignition within the building. If 602 is false, control may return to 601. The predetermined period may be, for example, 24 hours (1 day) or another suitable period.

[0100] At 604, the regulating module 328 determines whether the refrigeration system is on, thus enabling heating or cooling of the building. If 604 is true, control continues to 608. If 604 is false, the regulating module 328 can maintain the drift adjustment and return to 601.

[0101] At 608, the regulating module 328 determines the current operating mode of the refrigeration system. If the refrigeration system is operating in heating mode, control continues to 616. If the refrigeration system is operating in cooling mode, control continues to 612.

[0102] At 612, the regulating module 328 determines whether the refrigeration system has been operating in cooling mode for at least a predetermined period of time, such as approximately 5 minutes or another suitable period of time greater than zero. If 612 is true, control continues to 618. If 612 is false, control returns to 601, and the regulating module 328 maintains the drift adjustment unchanged. At 616, the regulating module 328 determines whether the refrigeration system has been operating in heating mode for at least a predetermined period of time, such as approximately 5 minutes or another suitable period of time greater than zero. If 616 is true, control continues to 620. If 616 is false, control returns to 601, and the regulating module 328 maintains the drift adjustment unchanged.

[0103] At 618, the drift module 408 determines a baseline measurement, such as the current measurement of the refrigerant leak sensor 140 or the average of the most recent X measurements of the refrigerant leak sensor 140 (e.g., a standard average, moving average, or weighted moving average). X can be, for example, the most recent 10 measurements or other suitable number of measurements, or all measurements from the refrigerant leak sensor 140 obtained within the last X time units (e.g., seconds, minutes, etc.). "Most recent" can refer to a sense of time relative to the current time.

[0104] At 620, drift module 408 determines a baseline cleaning measurement, such as the current measurement of refrigerant leak sensor 140 or the average of the most recent X measurements of refrigerant leak sensor 140 (e.g., a standard average, moving average, or weighted moving average). X can be, for example, the most recent 10 measurements or other suitable number of measurements, or all measurements from refrigerant leak sensor 140 obtained within the most recent X time units (e.g., seconds, minutes, etc.). "Most recent" can refer to a sense of time relative to the current time. After 618 and 620, control continues to 624.

[0105] At 624, drift module 408 determines drift adjustment based on baseline cleaning measurements (from 620) and baseline measurements (from 618). Initial measurements may be stored in memory. Drift module 408 may set drift adjustment based on or equal to the difference between the baseline measurement and the baseline cleaning measurement (e.g., baseline measurement minus baseline cleaning measurement).

[0106] At 628, the life-end module 440 can determine whether the drift adjustment (e.g., amplitude) is greater than a predetermined value. If 628 is true, the life-end module 440 can indicate that the refrigerant leak sensor is at or near the end of its service life and take one or more remedial actions at 632. At 632, the life-end module 440 can also reset the time period (compared to 602). If 628 is false, control can transfer to 636. At 636, the life-end module 440 can determine whether the drift adjustment (e.g., amplitude) has increased by more than a predetermined amount relative to the initial drift adjustment, or increased during each update in the last Y updates (at 624). Y is an integer greater than or equal to 2. If 636 is true, the life-end module 440 can indicate that the refrigerant leak sensor 140 is at or near the end of its service life and take one or more remedial actions at 632. If 636 is false, then at 640 the life-end module 440 can indicate that the refrigerant leak sensor 140 is not at or near the end of its life-end, and control can return to 601.

[0107] 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.

[0108] 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," "right next to," "on top," "above," "below," and "set." Unless explicitly described as "direct," when describing the relationship between the first and second components in the foregoing disclosure, the relationship can be a direct relationship where no other intervening components exist between the first and second components, or an indirect relationship (spatially or functionally) between the first and second components. As used herein, the phrases A, B, and C at least one 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."

[0109] In the accompanying drawings, the direction of the arrows, as indicated by the arrows, typically indicates the flow of information important to the illustration (e.g., 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 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 an acknowledgment of receipt of the information to component A.

[0110] In this application, including the following definitions, the term "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 combinations of some or all of the above, such as in a system-on-a-chip.

[0111] 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.

[0112] 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.

[0113] 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 on a carrier wave); the term computer-readable medium can therefore 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).

[0114] 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.

[0115] 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 contain a basic input / output system (BIOS) for interacting with the hardware of a special-purpose computer, device drivers for interacting with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0116] Computer programs 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 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 an example only, source code can be written using syntax from languages ​​including: C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java (registered trademark), Fortran, Perl, Pascal, Curl, OCaml, JavaScript (registered trademark), HTML5 (Hypertext Markup Language 5th Edition), Ada, ASP (Dynamic Server Web Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash (registered trademark), Visual Basis (registered trademark), Lua, MATLAB, SIMULINK, and Python (registered trademark).

Claims

1. A refrigerant measurement and control system, comprising: A refrigerant sensor for use in buildings and configured to measure the amount of refrigerant present in the air outside the building’s refrigeration system; as well as The adjustment module is configured as follows: The measured refrigerant dose is adjusted based on a first adjustment value to produce an adjusted measurement; and The first adjustment value is determined based on at least one of the following: Air temperature; Air pressure; Relative humidity of the air; The operating mode of the refrigeration system; The quantity measured by the refrigerant sensor changes over time; as well as Check whether the fan blowing air through the heat exchanger of the refrigeration system located inside the building is turned on; as well as The first adjustment value is set based on the measured refrigerant dose in response to determining at least one of the following conditions: The operating mode is in heating mode for the first predetermined time period; The process of pumping refrigerant out of the building has been completed; The operating mode has been switched from cooling mode to heating mode and refrigerant has been pumped out of the building; as well as The wind turbine has been connected for at least the second predetermined period.

2. The refrigerant measurement and regulation system of claim 1 further includes a leakage module configured to indicate the presence of a refrigerant leak based on the regulated measurement.

3. The refrigerant measurement and regulation system according to claim 1, wherein, The adjustment module is configured to determine the first adjustment value based on the air temperature.

4. The refrigerant measurement and regulation system according to claim 3, wherein, The adjustment module is configured to determine the first adjustment value based on the change in air temperature.

5. The refrigerant measurement and regulation system according to claim 1, wherein, The adjustment module is configured to determine the first adjustment value based on the air pressure.

6. The refrigerant measurement and regulation system according to claim 5, wherein, The adjustment module is configured to determine the first adjustment value based on the change in air pressure.

7. The refrigerant measurement and regulation system according to claim 1, wherein, The adjustment module is configured to determine the first adjustment value based on the relative humidity.

8. The refrigerant measurement and regulation system according to claim 7, wherein, The adjustment module is configured to determine the first adjustment value based on the change in relative humidity.

9. The refrigerant measurement and regulation system according to claim 1, wherein, The adjustment module is configured to: The measured refrigerant dose is further adjusted based on the second adjustment value to produce a further adjusted measurement; and The second adjustment value is determined based on the change in refrigerant dosage over time as measured by the refrigerant sensor.

10. The refrigerant measurement and regulation system according to claim 1, wherein, The adjustment module is configured to set the adjusted measurement based on either the measured cooling dose plus the first adjustment value or the measured cooling dose minus the first adjustment value.

11. The refrigerant measurement and regulation system according to claim 1, wherein, The adjustment module is configured to set the adjusted measurement based on the measured cooling dose multiplied by the first adjustment value.

12. The refrigerant measurement and regulation system according to claim 1, wherein, The adjustment module is configured to adjust the measured refrigerant dose based on at least two adjustment values, which are determined based on at least two of the following: The air temperature; The air pressure; The relative humidity of the air; The operating mode of the refrigeration system; The quantity measured by the refrigerant sensor changes over time; as well as Check whether the fan is turned on to blow air through the heat exchanger of the refrigeration system located inside the building.

13. The refrigerant measurement and regulation system according to claim 1, wherein, The adjustment module is configured to adjust the measured refrigerant dose based on an adjustment value determined based on each of the following: The air temperature; The air pressure; The relative humidity of the air; The operating mode of the refrigeration system; The quantity measured by the refrigerant sensor changes over time; as well as Check whether the fan is turned on to blow air through the heat exchanger of the refrigeration system located inside the building.

14. The refrigerant measurement and regulation system according to claim 1, wherein: The adjustment module is configured to adjust the measured refrigerant dosage based on the change in the amount measured by the refrigerant sensor over time; and The refrigerant measurement and adjustment system further includes a life-end module, which is configured to indicate that the refrigerant sensor is at the end of its service life when the magnitude of the change is greater than a predetermined value.

15. The refrigerant measurement and regulation system according to claim 1, wherein: The adjustment module is configured to adjust the measured refrigerant dosage based on the change in the amount measured by the refrigerant sensor over time; and The refrigerant measurement and regulation system further includes a life-end module configured to indicate that the refrigerant sensor is at the end of its lifespan when the magnitude of the change increases over at least a predetermined number of consecutive instances.

16. A method for measuring and adjusting refrigerant, comprising: The amount of refrigerant present in the air outside the building's refrigeration system is measured by a refrigerant sensor used in the building; The measured refrigerant dose is adjusted based on a first adjustment value to produce an adjusted measurement; The first adjustment value is determined based on at least one of the following: Air temperature; Air pressure; Relative humidity of the air; The operating mode of the refrigeration system; The quantity measured by the refrigerant sensor changes over time; as well as Check whether the fan blowing air through the heat exchanger of the refrigeration system located inside the building is turned on; as well as The first adjustment value is set based on the measured refrigerant dose in response to determining at least one of the following conditions: The operating mode is in heating mode for the first predetermined time period; The process of pumping refrigerant out of the building has been completed; The operating mode has been switched from cooling mode to heating mode and refrigerant has been pumped out of the building; as well as The wind turbine has been connected for at least the second predetermined period.

17. A refrigerant measurement and regulation system, comprising: A refrigerant sensor for use in buildings and configured to measure the amount of refrigerant present in the air outside the building’s refrigeration system; as well as The adjustment module is configured as follows: The measured refrigerant dose is adjusted based on a first adjustment value to produce an adjusted measurement; The first adjustment value is determined based on at least one of the following: Air temperature; as well as Relative humidity of the air; and The first adjustment value is set based on the measured refrigerant dose in response to determining at least one of the following conditions: The operating mode is in heating mode for the first predetermined time period; The process of pumping refrigerant out of the building has been completed; The operating mode has been switched from cooling mode to heating mode and refrigerant has been pumped out of the building; The wind turbine has been connected for at least the second scheduled period.

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