Patent Application
20250044267
The subject matter of the present invention, as the title of the invention establishes, is a sensor device for various substances suspended in the surrounding air in such a way that it reports their presence, as well as their concentration and consequently activates the relevant actuators to improve the quality of said air in the event the latter degrades or worsens. The device subject matter of the invention has two man-machine interfaces, namely, one direct interface by having nominated and scaled indicators in a range of colours to inform and alert of quality levels, and another virtual interface by also being able to be informed by means of a computer application, which can be installed on Smartphone-type mobile terminals or on traditional computers. Connectivity with the exterior, apart from the power supply via USB connector or the conventional 230Vac electrical grid, consists of 2+1 wires under the Modbus protocol, digital and analogue outputs and digital inputs.
The present invention is characterised by the special technical features of the invention, as well as its joint arrangement and its functional interaction such that, on the one hand, it is possible to obtain 8 variables (5 measured and 3 calculated) of the surrounding atmosphere and, on the other hand, act on up to 3 devices capable of controlling these variables in case one or some of them exceed the established limits. These limits have been taken by national and international references and standards, such as the European Environment Agency (EEA), the German Environment Agency (UBA), the National Institute for Safety and Hygiene at Work (INSHT) and the American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE).
Therefore, the present invention is limited within the field of measurement, regulation and control devices, and particularly among devices used in environmental air quality.
Electronic devices for measuring the different chemical and physical variables that determine temperature, density, volume or percentage exist well into the 20th century, starting with the physical temperature variable at the earliest and ending with the latest, already at the end of the 20th century, with more complex sensors capable of sensing particulate matter of up to 1 microgram per cubic meter or volatile organic matter.
Once sensors of this type were developed, they evolved into sensor-actuators, which actively participate in control or regulation. For example, sensing CO2, in such a way that when a certain threshold is exceeded, a normally open contact of a relay is closed, intended to actuate a ventilation flap opening or an aeration motor.
As sensors have been miniaturised and diversified, more versatile devices have emerged, encouraged in turn by global concern due to pollution, poor environmental quality or pathogenic substances suspended in the air such as the SARS-COV-2 virus.
Although there are many developments in measuring devices, there are not so many meter-actuators, which tend to have few physical-chemical variables, the most numerous being CO2 sensor-actuators, typically activating from a volumetric concentration threshold of parts per million (ppm), which is usually adjustable.
However, all existing means for controlling and regulating environmental air quality present aspects that can be improved, such as:
Therefore, the object of the present invention is to overcome, on the one hand, the drawbacks mentioned, and, on the other hand, to incorporate a novel device into the state of the art, for which, taking into account its benefits, a comparatively functional parallelism has not been found, developing a measurement, regulation and control device for the environmental air quality such as the one described below and is included in its essential nature in its claims.
The subject matter of the present invention is an air quality sensor-actuator device that monitors various physical and chemical variables, controls up to 2 external devices and regulates by means of 0-10V control any machine that has this control input, communicates to the Internet via Wi-Fi with any 2.4 GHz router and has RS485 serial connectivity for integration thereof into open source ModBus.
The air quality sensor-actuator is a device that, on the one hand, measures different variables concerning the air by means of a series of sensor means, in addition to carrying out a series of calculations using processing means and, depending on the data obtained, send command and actuation signals on external devices. It also has a human-machine interface to display the quality of the different measured parameters and connectivity with the outside through either a physical or wired connection or through a wireless connection.
The sensor means that the device subject matter of the invention has are: a temperature sensor, a relative humidity sensor, a particulate matter sensor that measures particle sizes of 1 micron, 2.5 microns and 10 microns, another sensor for measuring volatile organic compounds (VOC) and a fifth sensor for measuring CO2.
The processing means are responsible for calculating absolute humidity, dew point and thermal comfort.
In a possible embodiment, the command and actuation signals comprise two analogue outputs to act on a ventilation device and the other to act on an air purification device.
It also has a 0-10 Volt control output intended for climate or ventilation regulation, adjusting the flow rate thereof depending on the levels reached.
The human-machine interface for displaying the quality of the different measured parameters consists of a central circle illuminated with different colours depending on the quality of the parameters, a series of backlit acronyms that can be selected by means of a push button, where the backlit acronyms are AQ, PM, VOC and CO2 that correspond to air quality, particle size, volatile organic compounds, and CO2 level.
The sensor-actuator that is the subject matter of the invention is connected to the conventional 230Vac electrical grid, it also has an alternative 5V power supply via a micro USB type B female connector; an RS485 serial port with ModBus protocol including a parallel output with the input for possible Daisy Chain connectivity; a 2.4 Ghz Wi-Fi connection integrated internally into the hardware of the device to connect to a standard 2.4 GHz router; two digital outputs, the first is a normally open contact and the second is a dual contact that offers normally open and closed switching with respect to a common switching; an analogue output that offers a direct current in the range of 0 to 10 Vdc; two digital inputs: DI1, which when connected to ground interacts with the device to detect whether there is pressure in the ducts (through a pressure switch), in the event there is no pressure in the air ducts the device receives a closure of DI1 with GND and will report in the APP warning of this event, and DI2 which when connected to ground (GND) opens the contacts DO1 and DO2, shutting down the machinery that is connected to these outputs. Its function is intended to cause an external general shut-down coming from, for example, a hotel room card holder, window opening sensors or a simple external general shut-down switch; a man-machine interface arranged on the front that consists of illumination by circular LED diffuser showing the measurement levels in 5 colours, this circle with white light would report any operating anomaly. A small star icon is used to inform that the contact DO2 has been closed and a level 3 or higher of VOC or PM has been reached, that is, the surrounding atmosphere of the device is being purified. it is to indicate or consult what is being measured. A push button to consult in turn the variable desired, shown on the front with the acronyms AQ, PM, VOC and CO2 in white. There are five levels to be shown in colours in all the variables, namely:
The firmware of the device offers a 5-colour indication of the levels by thresholds in the central circle, with blue being considered as excellent (level 1), green as normal (level 2), yellow as average (level 3), orange as poor (level 4) and red as bad (level 5). The CO2 levels, VOC levels, and the worst of the particulate matter measurements PM1, PM2.5 or PM10 can be checked by using the push button. A fourth option of those available for display is the overall air quality level, named by the acronym AQ on the device and representing the worst of any of the previous variables.
The hardware of the device that is the subject matter of the invention integrates a VOC sensor, a CO2 sensor, a particulate matter sensor that measures sizes of 1, 2.5 and 10 microns, a thermopile temperature sensor and a relative humidity sensor as sensor elements inside the casing and integrated into the electronic unit. With these measurements, the device firmware, in addition to offering sensor measurements, calculates the dew point in degrees Celsius and the level of thermal comfort, divided into five levels. These comfort levels are based on the RH/T diagram (Relative humidity in percentage/Temperature in degrees Celsius) of the ANSI ASHRAE 55 standard (Thermal Environmental Conditions for Human Occupancy), published in its first edition in 1966 and constantly updated. This ANSI standard establishes ranges of indoor environmental conditions to achieve acceptable thermal comfort for building occupants. This diagram divides the RH/T relationship into three periods of the year: spring-autumn, summer and winter.
The temperature measurement is not carried out inside the casing of the device, since the sensing is performed through a thermopile sensor, based on the reflection of the infrared spectrum of the matter facing it: air, floors, ceilings, furniture and people. This sensor is capable of making a pseudo thermal digital image of the entire room in front of it. A microprocessor internal to the sensor continuously runs an algorithm resulting in an average temperature of the volume of the room being measured. This type of sensor, called thermopiles, was technologically developed and popularised thanks to the manufacture of tympanic thermometers in order to faithfully measure body temperature. Its operation is based on the studies of Leopoldo Nobili (1784-1835) of the thermoelectric effect when measuring infrared radiation (IR) with two Bismuth and Antimony contacts, as well as on meeting the formula for the maximum wavelength emitted by the bodies, by Wilhelm Wien (1864-1928):
The appearance of Planck's law (Max Planck 1858-1947) on the radiation of a black body, where it is stated that it absorbs all wavelengths, emitting only infrared radiation representative of its temperature, was the last necessary theoretical link so that this technology could be developed. The construction of this type of sensor consists of: a metal capsule containing a Bismuth-Antimony (Bi-Sb) substrate, a special filter for the radiation that is intended to be absorbed (IR) and a microprocessor circuit. The Bi-Sb substrate is a matrix of rows and columns, which can reach (depending on the manufacturer's model) up to 200 cells, each offering its own measurement. These measurements are managed by the microprocessor internal to the sensor to offer a final measurement at regular intervals (adjustable depending on the manufacturers). The result is a sensor that reports the temperature of the matter facing it, regardless of whether it is a solid or a gas, such as Nitrogen. In the case of gases, a correction factor is applied depending on the type of gas since, for example, Neon only emits 62% IR radiation, while Nitrogen emits 100%. It is therefore ideal for measuring the temperature of the surrounding air, as it contains 80% Nitrogen. The aperture angle of the measurement window ranges from a 10° cone (ideal for tympanic thermometers) to 90°, ideal for measuring large rooms, as is the case here.
The digital outputs intended for the actuation thereof depending on the current level: 1,2,3,4 or 5, are mainly intended to start ventilating and purifying at the moment in which the level changes from normal level to average level, although the final use of these contacts is left to the free choice of the user or final installer. The digital output 1 is actuated whenever any of the variables crosses the threshold from normal to average, in order to move the air in the room. However, the digital output 2 is not actuated if it is only the CO level 2 that has crossed over to an average level. This output is therefore actuated if the change from normal to average is due to VOC or PM. When digital output 2 is actuated, the symbol of the white stars lights up on the front interface to inform the user that purification is being performed. In this way, air quality is improved by renewing it by ventilation, totally or partially coming from the exterior with the digital output 1 and is purified with the digital output 2 actuating ionisers, hydrogen peroxide generators, ozonisers, active static electricity filters, etc.
The analogue output consists of a typical 0 to 10 volt output and is implemented to be able to maintain, increase or decrease the air flow to be renewed and/or purified depending on the current level. By default, in the excellent and normal levels, a constant value of 1.5V is maintained to maintain a minimum level of ventilation, required by most standards in European countries, even if there is an excellent or normal level of air quality. In the average level range, a voltage of 3.3 volts is imposed, in the poor level range a voltage of 6.6V is applied to this output and in the bad level interval 9.9 volts are applied.
The parametric values that determine the level changes (colours), the voltage values of the analogue output at each level and the RGB values of the colours of each level can be modified by accessing the corresponding Modbus registers using any of the many free programmes which are accessible on the Internet.
These parameters are preset by default, in 5 classifications, from best to worst: 1=Excellent, 2=Good, 3-Average, 4=Poor and 5=Bad. An identifying colour corresponds to these five classifications, namely: Blue, Green, Yellow, Orange and Red, respectively. The correspondence between the classifications and parametric values of the variables are the following:
The space of the quadrant of the diagram is divided into 5 zones, characterising the central core of the shading of the table as the most comfortable (1=Excellent=Blue), to the least good (5=Bad=Red). The overlapping area between winter and summer is considered spring-autumn, therefore having 3 slightly different divisions:
The resulting level of comfort is not reflected visually on the device itself, but is displayed unequivocally in the Internet-accessible application associated with said device. This application connects to a cloud where the level of comfort is calculated based on relative humidity, temperature and date of the year, such that the algorithm uses one of the three tables above. This information, its calculation and classification, is shown to the user both descriptively and in the form of colours, being a function of the sensed temperature and relative humidity variables.
On the front of the device, four variables will be displayed using a circle of RGB light. The display of the one that is measured is executed by switching in turn, by pressing the lower button. The first variable represents a general assessment, referred to using the acronym AQ, and shown with a colour of the five available colours equivalent to the worst of the other three. The second variable is the particulate matter, called PM. The device has the capacity to measure 3 sizes of particulate matter, the worst of the three being the one that defines the colour to be displayed. The third variable is the parts per billion (ppb) of volatile organic compounds measured by the device, referred to using the acronym VOC. The fourth variable is CO2, (Carbon dioxide), measured by the device in parts per million and referred to in the device as CO2. These five colours are the ones that will be displayed on the front of the device. The variables PM1, PM2.5, PM10, VOC, CO2, Temperature and Relative Humidity are simultaneously captured in the device of the present invention.
The relationship between the measured variables and the consequent actuation of the 3 active outputs, in such a way that a degradation of the air quality is resolved in the minimum possible time due to the actuators, is the following:
Any of the PM or VOC variables activate the two digital outputs simultaneously when the status changes from Normal status (green) to Average status (yellow), or worse. Changing from Average to Normal deactivates them. The firmware of the device contains a hysteresis of the values to avoid switching between regressive values, with 5 units in each band.
The CO2 variable only activates the first digital output when changing from Normal (green) to Average (yellow) or worse. Changing from Average to Normal deactivates it. The analogue output provides a constant voltage of 1.5V in its Excellent and Normal levels, in order to maintain constant ventilation even when the air surrounding the device is of good quality. Any of the variables (PM, VOC or CO2) that change to the Average state will impose an analogue output voltage of 3.3V. Likewise, if one of them changes to the Poor state (Orange), the analogue output voltage will rise to 6.6V. Ultimately, if any of them were in the Bad state (Red), the analogue output voltage will be 9.9V. These voltages are applied to ventilation machines or air conditioning machines or heat recovery machines that have an input of 0 to 10V to control the air flow, 0 V typically being the shut-down machine and 10V at flow.
The main strategy for restoring the air quality in the event of degradation is: ventilate only, if CO2 is the variable that causes this degradation (activating a single digital output). Ventilate and purify by activating the two digital outputs, one to ventilate and the other to activate a purifier, the combination of a hydrogen peroxide generator with ionizers such as flocculants being highly recommended, all with a small percentage of ozone (O3) less than 0.01 ppm to ensure its safety.
As a complementary strategy, controlling the flow of air forced by machines that have control from 0 to 10V is available, such that, the greater the degradation of the air, the greater the flow.
Except when indicated otherwise, all of the technical and scientific elements used in this specification have the meaning commonly understood by a person with average skill in the art to which this invention belongs. When this invention is put into practice, methods and materials may be used that are similar or equivalent to the ones described in the specification.
Throughout the description and the claims, the word “comprise” and its variants are not intended to exclude other technical features, additions, components or steps. For those skilled in the art, other objects, advantages and features of the invention will be deduced from both the description and the practical use of the invention.
As a complement to the description provided herein, and for the purpose of helping to make the features of the invention more readily understandable, in accordance with a preferred practical exemplary embodiment thereof, said description is accompanied by a set of drawings which, by way of illustration and not limitation, represent the following.
The numbered elements of the figures are listed below:
1′-Device subject matter of the invention application in a rear perspective thereof.
On the rear face (1′) it can be seen that the device comprises:
On the front face (1) there is a series of air quality indicator means or man-machine interface and which comprises:
In
The connection of the external devices must be done by closing the normally open contacts of the relays of the device corresponding to the outputs DO1 (5) and DO2 (6). The use of the outlet DO1 for ventilation and the outlet DO2 for purification is highly recommended. The connection of the digital inputs is intended to protect the installation from anomalies or cause a general outage for whatever reason. The connection of the RS485 serial port under the ModBus protocol will be implemented when multiple devices are to be connected, and can be integrated into a BMS system as a master, with the devices being slaves. The wiring of this connection must be done with standard RS485 shielded and twisted cables in pairs, where wires A+ and B− are a twisted pair and the GND wire is connected to the shield of the cable. The device provides an input connection, which is a RS485 serial port (3) and another output connection (4) to facilitate the Daisy Chain topology. During the installation and by means of the computer application, the device furthest away in distance is activated as the one that electronically activates the 1200 ohmic terminal, to ensure the quality of the serial data. If the external element responsible for impelling the air contains a 0-10V input, which regulates from lower to higher voltage, the air flow from lower to higher, the analogue output (7) of the device can be connected to this input, modulating in this way the flow rate necessary to ventilate depending on the level of deterioration in air quality, that is, the higher the deterioration in air quality, the greater the impeller flow. If the device is used by means of an application on a smartphone, tablet or similar, the integrated Wi-Fi module must be activated by reading the QR code affixed to the back housing. The Internet connection is executed using WPS with the router to be connected or by inserting the router data (router identifier and password) in the application. Using the same method, an unlimited number of devices (26) can be registered in the same application installed on the user's smartphone, and must have coverage with a router. In this way, said user could, for example, control the air quality of their office, workshop, home, etc., in the same application.
| Number | Date | Country | Kind |
|---|---|---|---|
| U202132498 ES | Dec 2021 | ES | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/ES2022/070013 | 1/17/2022 | WO |
