Device for monitoring a refrigeration unit

Abstract

The invention relates to the field of refrigeration equipment, specifically to devices for monitoring the state of the refrigeration units. The device comprises a set of sensors that monitor the content of gases emitted by food products during storage, means for transmitting sensor signals to a controller (11) that analyzes gas sensor signals and transmits analysis results to external devices. The set of sensors includes a hydrogen sulfide sensor (1), an ammonia sensor (2), a carbon dioxide sensor (3), an ozone sensor (4), a VOC sensor (5), a temperature sensor (6), a moisture sensor (7), a vibration sensor (8), and a sound sensor (9). The technical effect of the invention is the creation of an autonomous device for continuous monitoring of the general condition of the refrigeration units, enabling early detection of food spoilage and equipment malfunctions.

Description

[0001] IPC: F25B 33 / 00; F25D 29 / 00

[0002] Device for monitoring a refrigeration unit

[0003] The invention relates to refrigeration equipment, in particular, to the devices for monitoring the status of the refrigeration unit.

[0004] Traditional refrigerators usually only serve as temporary storage for food. Their disadvantage is that they cannot inform the user about the actual conditions of food storage in the refrigerator, the presence of addled or deteriorated products, as well as the condition of the refrigeration unit itself as a device that provides appropriate conditions for food storage. This leads to significant food losses, economic losses, and, more importantly, affects human health.

[0005] It is known that in 2010, food losses and waste in the United States amounted to about 31 percent of the total food supply. This is equivalent to $162 billion in waste or losses.

[0006] Therefore, there is a need for inexpensive and versatile devices for continuous monitoring of refrigeration units, which allow the user to control the parameters of the gas environment in the internal volume of the refrigeration unit, characterizing the condition of the stored food products, as well as the condition (serviceability) of the refrigeration unit itself as a device that provides appropriate conditions for food storage.

[0007] Gas analyzers are widely used to determine the components (target gases) present in the gas environment inside the refrigeration unit, examples of which are given below.

[0008] For example, a well-known portable gas mixture analyzer (UA2408007, IPC: GOIN 27 / 12, priority date: 11.09.2008).

[0009] The analyzer contains:

[0010] Detection chamber with pipes;

[0011] Piezoelectric sensor for fixing the components of the gas mixture, located inside the detection chamber;

[0012] A device for exciting vibrations and recording piezoelectric sensor signals (frequency meter) located inside the detection chamber; And a microprocessor for recording and converting piezoelectric sensor signals and transmitting them to a digital display.

[0013] An exciter and a frequency meter are driven independently from the built-in battery. All parts of the gas analyzer are connected in one miniature housing, on the top panel of which there is a detection chamber cover, a digital display, and a light indicator of device readiness for operation. The power button and charger input are located on one of the side panels.

[0014] This analyzer is designed for rapid analysis of gas mixture samples for determining the concentration of gases that are markers, in particular, of food quality. This analyzer is not suitable for continuous monitoring of the gas environment of the refrigeration unit chamber.

[0015] A device for preserving the freshness of vegetables with a sensor is known (US5609096 IPC: A01F 25 / 00, A23B7 / 148, A23B7 / 152, A23L3 / 3418, priority date: 15.12.1994).

[0016] The device for preserving the freshness of vegetables contains:

[0017] A device for determining the freshness of vegetables, which is a gas sensor with an electrical signal output which determines the presence and concentration of target gases released by vegetables during storage;

[0018] And a microprocessor that receives an electrical signal from the vegetable freshness detection devices determines the condition of the vegetables and gives a control signal according to the result of the vegetable condition detection.

[0019] A microprocessor recognizes the point in time when the vegetable is still fresh and the point in time when the vegetable begins to deteriorate according to the electrical signal from the specified freshness detector.

[0020] The controlled parameters of vegetable freshness are at least one of the following: temperature, humidity, pressure, 02 and CO2 content, the amount of anions, and the amount of ozone.

[0021] This device is focused only on preserving the freshness of vegetables by controlling the parameters that affect the process of decomposition (injury) of vegetables. The limited functionality of the device does not provide the possibility of comprehensive monitoring of the refrigeration unit including monitoring the condition of many types of stored products, the degree of contamination of the refrigerator compartment as well as the condition (serviceability) of the refrigeration equipment itself, as a device that ensures the storage conditions of products.

[0022] The system for detecting food quality in a refrigeration unit is also known (CN108872493, IPC: F25D 29 / 00, G01D 21 / 02, GOIN 33 / 02, priority date: 23.05.2018).

[0023] The food quality detection system includes a monitoring module, memory, data processor, data transmission module, monitoring system controller, display screen, and buzzer.

[0024] A monitoring module is connected to the memory and data processor via the data module. A monitoring system controller is connected to the monitoring module to control the operating status of the monitoring module. A data processor is connected to the display screen and buzzer.

[0025] The monitoring module includes a temperature sensor, a humidity sensor, a gas phase sensor, and a liquid phase sensor.

[0026] The gas phase sensor includes one or more sensors: ethanol sensor, alkane sensor, combustible gas sensor, carbon monoxide sensor, and carbon dioxide sensor.

[0027] The liquid phase sensor consists of a nanofoam copper and platinum electrode to form a detection electrode system; it is used to detect volatile food components dissolved in the detection liquid.

[0028] All detectors are connected to the monitoring system controller. The monitoring system controller compares and corrects the detection, gas phase sensor, and liquid phase sensor data according to the temperature and moisture content in the refrigeration unit.

[0029] The limited functionality of this system, namely, only assessing the freshness of products by monitoring the gases emitted by products and adapting storage conditions, does not provide the possibility of comprehensive monitoring of the refrigeration unit including control of the condition of stored products, the degree of contamination of the refrigerator compartment, as well as the condition (serviceability) of the refrigeration equipment itself as a device that ensures the storage conditions.

[0030] A device for determining the freshness of food products is also known (WO2022 140634, IPC: F25D 29 / 00, GOIN 33 / 00, priority date: 20.04.2020).

[0031] The device contains:

[0032] A system of gas sensors configured to generate many output signals based on the level of detected gases, wherein said gas sensor system comprises a plurality of gas sensors configured to determine the composition of the gas mixture emitted by food products;

[0033] A detection system that is functionally linked to the specified gas detection system and is configured to receive and process a plurality of output signals to generate a plurality of gas mixture analysis results;

[0034] A display unit functionally connected to the specified detection system designed to display information about the freshness of food products based on the results of analysis.

[0035] The gas detector contains a pad; a pair of electrodes placed on the pad; a thin conductive film placed on the pair of electrodes, and a gas-sensitive film arranged to surround a conductive thin film and create a difference in electrical conductivity when it reacts with the target gas.

[0036] The benefits of using a sensor network include selectivity to recognize multiple gases from different foods. This allows consumers to use a single gas detector system to determine the freshness of any perishable food, including meat, fish, dairy products, fruits, vegetables, etc.

[0037] The system allows only monitoring of food quality but does not provide the ability to control the condition (serviceability) of the refrigeration unit itself as a device that ensures food storage conditions.

[0038] A gas analyzer for a refrigerator is chosen as a prototype (US2017160005, IPC: F25D25 / 00; F25D 29 / 00; GOIN 21 / 78; GOIN 21 / 80, priority date: 02.04.2015). The object of the invention is to create a gas analyzer comprising a plurality of gas sensors that change color as a result of reaction with different predefined target gases to measure independently the amount of each target gas.

[0039] The gas analyzer includes:

[0040] A gas sensor with several gas detectors that change color as a result of a reaction with specified target gases;

[0041] An image detector for color detection of multiple gas sensors;

[0042] A transmitter as a device for outputting data about each color detected by the image detector to the controller;

[0043] A controller for determining the state of target objects (food) based on images of gas sensors received from an image detector;

[0044] A display for displaying information on the condition of products based on the image of gas sensors received from the image detector.

[0045] The target gas includes gas generated in the process of food storage, namely hydrogen sulfide (H2S), ammonia (NH3), ethylene (C2H4), trimethylamine (N(CH3)3), acetic acid (C2H4O2), and carbon dioxide (CO2).

[0046] A gas sensor includes:

[0047] Base;

[0048] Multiple gas detectors located on the base and designed to detect different target gases; each of the gas detectors is decolorized by reacting with a predefined target gas.

[0049] Every gas detector includes:

[0050] Hydrophilic membrane with a solution for detecting a given target gas (the solution is a pH indicator) that changes color in response to the pH change that occurs when it reacts with the given target gas;

[0051] Hydrophobic membrane permeable to the target gases;

[0052] Transparent gas-tight membrane that covers several gas detectors.

[0053] The controller is designed to store data on the color change of a set of gas detectors and data on the condition of products based on the color change of gas detectors, wherein the controller determines the difference between the color of the gas detector before exposure to the target gas and the color of the gas detector obtained after exposure to the target gas using the image received from the image sensor, determines the status of the products based on the color difference using previously stored data.

[0054] The display is a means of notifying the user of the state of the food stored in the refrigerator.

[0055] The functions of this gas analyzer are limited only to monitoring the freshness of products. The specified gas analyzer does not provide control of the general contamination of the refrigerator compartment, as well as control of the condition (serviceability) of the refrigeration unit itself as a device that creates conditions for storing food. In addition, the gas analyzer has a complex design, as it requires the use of an image detector to detect the colors of a plurality of gas detectors, and a device for converting the colors of gas detectors into electrical signals to transmit information about the status of gas detectors to the controller.

[0056] The invention is based on the task of creating an inexpensive, autonomous, and universal (independent of the design features of the refrigeration unit) device for continuous monitoring of the general condition of the refrigeration unit by monitoring the gas environment of the internal space of the refrigeration unit and the condition (serviceability) of the refrigeration unit itself as a device that provides conditions for food storage.

[0057] The task is solved by the fact that in a device for monitoring a refrigeration unit, which includes a set of sensors that monitor the content of gases released by food products during storage, means for transmitting sensor signals to the controller, a controller that analyzes gas sensor signals and transmits the analysis results to external devices, in accordance with the invention, the sensor set additionally includes an ozone sensor, volatile organic compounds sensor, temperature sensor, sensor of moisture, vibration sensor, and sound (noise) sensor.

[0058] These features are essential features of the invention, as they are necessary and sufficient to achieve the task — creation of an inexpensive, versatile device for continuous monitoring of the general condition of the refrigeration unit by controlling the gas environment in the internal space of the refrigeration unit and the condition of the refrigeration unit itself as a device that provides conditions for food storage.

[0059] This can be explained by the following:

[0060] The general condition of the refrigeration unit is determined by the parameters of the gas environment in the internal volume of the refrigeration unit, as well as the condition (serviceability) of the refrigeration unit itself as a device that provides conditions for food storage. It is known that the sources of contamination of the gas environment in the refrigeration unit chamber are stale and addled products (about 40% of contaminants), general camera contamination, including spilled liquids (about 25% of contaminants), decomposition of product packages (about 15% of contaminants), ozone residues due to sanitary ozonation of the refrigeration unit chamber, and other sources of contamination. It is known that the obvious signs of a refrigeration unit malfunction are violations of the temperature and humidity regimes in the chamber, and the presence of vibrations and extraneous sounds (noise) during the operation of the refrigeration unit. Gas sensors inform about the presence and amount of gases emitted by food products during storage, an ozone sensor informs about ozone residues after sanitizing the food storage chamber by ozonation, and the VOC sensor informs about the presence of substances emitted by general contamination of the refrigeration unit chamber, decomposition of food packages, emissions from plastic parts and other sources of contamination. Temperature, moisture, vibration, and sound (noise) sensors inform about the condition (serviceability) of the refrigeration unit itself as a device that provides appropriate conditions for food storage. The specified set of sensors is sufficient to assess the general condition of the refrigeration unit by monitoring the gas environment in the internal space of the refrigeration unit and the condition of the refrigeration unit itself as a device that provides conditions for food storage.

[0061] It is advisable that the set of sensors that monitor the content of gases emitted by food products during their storage includes at least a hydrogen sulfide sensor, ammonia sensor, and carbon dioxide sensor.

[0062] It is reasonable to use sensors with an electrical signal output, which simplifies the design of the device. It is possible to design the sensor signal transmission equipment and the controller as a single module.

[0063] It is recommendable to make the device in the form of a separate closed housing with openings for the flow of gases to the sensors, in the internal volume of which the compartments are made, in which the device elements are located, with the sensors located in the peripheral compartments, and the means of transmitting sensor signals and the controller are located in the central isolated compartment of the housing. This design of the housing and the arrangement of the device elements in the housing are optimal for ensuring the device's efficiency and compactness.

[0064] Below is an example of a device for monitoring a refrigeration unit with references to the drawings that show:

[0065] Fig.l — Device for monitoring of refrigeration unit, block diagram of the device.

[0066] Fig.2 — Device for monitoring of refrigeration unit, design features of the device execution.

[0067] Fig.3 — Device for monitoring of refrigeration unit, a photo of the finished product's appearance.

[0068] Device for monitoring of refrigeration unit (Fig.l) contains:

[0069] Sensor kit that includes a hydrogen sulfide (H2S) sensor 1, an ammonia (NH3) sensor 2, a carbon dioxide (CO2) sensor 3, an ozone (03) sensor 4, a volatile organic compounds (VOC) sensor 5, temperature sensor 6, moisture sensor 7, vibration sensor 8, and sound (noise) sensor 9;

[0070] Switching processor 10 as a means of transmitting sensor signals to the controller;

[0071] Controller 11 ;

[0072] Power supply 12;

[0073] Lines 13 connecting the outputs of the controller 11 to external devices;

[0074] Hydrogen sulfide (H2S) sensor 1, ammonia (NH3) sensor 2, and carbon dioxide (CO2) sensor 3 are designed to determine the amount of target gases released by food products during storage and possible spoilage in the refrigeration unit. In this example of device implementation, the following is used:

[0075] - As sensor 1 of hydrogen sulfide (H2S) — sensor model ME4-H2S;

[0076] - As sensor 2 of ammonia (NH3) - sensor model TGS826, used in refrigeration units;

[0077] - As sensor 3 of carbon dioxide (CO2) - non-dispersive infrared CO2 sensor, model

[0078] SCD30.

[0079] Ozone sensor 4 (03) monitors the harmful impurity ozone in the gas environment of the refrigeration unit after sanitizing the storage chamber for ozonation products.

[0080] In this example, the MQ-131 module is used as the ozone (03) sensor 4 , designed to determine the concentration of ozone in the air.

[0081] The sensor 5 of volatile organic compounds (VOCs), which are a large group of chemical compounds consisting of various carbon-containing gases, informs about the presence of substances emitted by general contamination of the refrigeration unit chamber, decomposition of food packages, plastic parts in the refrigerator chamber and other sources of contamination. In this device example, the VOC sensor 5 is a semiconductor SGR30 (VOC) sensor.

[0082] The readings of sensors 1-5 allow assessing the state of the gas environment in the internal volume of the refrigeration unit.

[0083] The functional purpose of sensors 6, 7, 8, 9 is indicated by their names: temperature sensor 6, moisture sensor 7, vibration sensor 8, and sound (noise) sensor 9.

[0084] In this example of device implementation, the following is used:

[0085] - As temperature sensors 6 and moisture sensors 7 — digital temperature and moisture sensor SHT-31D module;

[0086] - As sensor 8 of vibrations — three-axis ADXL345 accelerometer;

[0087] - As sound (noise) sensor 9 — SPW2430 module.

[0088] The readings of sensors 6-9 allow assessing the condition (serviceability) of the refrigeration unit as a device that provides appropriate storage conditions for food.

[0089] The outputs of these sensors 1-9 are electrical signals, which simplifies the design of the device. The sensor models 1-9 are examples only. Other sensor models that perform similar functions can be used.

[0090] A set of the specified sensors 1 -9 is sufficient to assess the general condition of the refrigeration unit including assessing the condition of the stored products, the degree of contamination of the chamber, as well as the condition (serviceability) of the refrigeration equipment as a device that provides appropriate storage conditions for the products.

[0091] The switching processor 10 is designed to read the readings of sensors 1-9, process signals including the conversion of analog signals of sensors 1 -9 into digital form, and further transmission of the processed signals to the controller 11.

[0092] The controller 11 is designed to analyze the signals of sensors 1 -9 received from the switching processor 10 by comparing the sensor signals with the set thresholds stored in the controller's memory to assess the general condition of the refrigeration unit, including the state of the gas environment in the internal volume of the refrigeration unit, the degree of contamination of the refrigeration unit chamber, the condition of the stored food, as well as the condition (serviceability) of the refrigeration unit itself as a device that provides conditions for food storage. These functions are performed in accordance with the program embedded in the controller 11 with a given algorithm of actions. The switching processor 10 and the controller 11 can be made as a single multifunctional module (not shown in the block diagram). In this example, the multifunctional controller of the ESP32 model is used as such a module with integrated WiFi and Bluetooth systems.

[0093] As a power source 12, replaceable batteries or a rechargeable battery is used, which ensure the autonomy of the device.

[0094] These elements of the device are functionally interconnected. The outputs of the sensors 1-9 are connected to the inputs of the switching processor 10, the outputs of which are connected to the inputs of the controller 11. The output signals of the controller 11 containing information about the state of the refrigeration unit are transmitted via lines 13 to external devices. As external devices, a computer for remote control of the refrigeration unit, a display and wireless communication means (Wi-Fi, Bluetooth) can be used to notify the user of the state of the refrigeration unit, as well as control devices for the refrigeration unit, for example, a device for shutting down the refrigeration unit in the event of an emergency.

[0095] Figure 2 shows a construction diagram of the device.

[0096] The device is made in a plastic housing 14 with air vents 15 for access of gas medium to sensors 1, 2, 3, 4, 5, 6, and 7, and stiffening partitions 16, forming compartments 17, 18, 19, 20, in which the elements of the device are located. The sensors 1, 2, 3, 4, 5, 6, 7, 8, and 9 are located in peripheral compartments 17, 18, and 19; and microprocessor 10, controller 11 and power supply 12 are located in the central isolated compartment 20. The housing 14 has a free space 21 for installing additional sensors, if necessary. A removable lid (not shown) covers the housing cavity 14. The specified design of the housing 14 and the arrangement of the device elements in the housing 14 are optimal for ensuring the operability and compactness of the device.

[0097] Fig. 3 shows a photograph of the appearance of the finished product.

[0098] The practical application of the device for monitoring the refrigeration unit allows reducing the loss of food products because of their spoilage, predicting and extending the shelf life of products while maintaining their freshness, maintaining the cleanliness and hygiene of the refrigeration unit, reducing pollutant emissions and negative impact on the environment, and ensuring normal operating conditions of the refrigeration unit.

Claims

Claims1. Device for monitoring a refrigeration unit, which includes a set of sensors that monitor the content of gases emitted by food products during their storage, means for transmitting sensor signals to the controller and a controller that analyzes gas sensor signals and transmits analysis results to external devices, characterized in that, the set of sensors additionally includes an ozone sensor, a volatile organic compound sensor, a temperature sensor, a moisture sensor, a vibration sensor, and a sound sensor.

2. Device according to clause 1 characterized in that, the set of sensors, that monitor the content of gases emitted by food during storage, comprising at least a hydrogen sulfide sensor, ammonia sensor, and carbon dioxide sensor.

3. Device according to clause 1 characterized in that, the output signals of the sensors are electrical signals.

4. Device according to clause 1 characterized in that, the sensor signal transmission means and the controller are designed as a single module.

5. Device according to clause 1 characterized in that, it is made in the form of a separate closed housing with openings for the flow of gases to the sensors, the internal volume of which contains the compartments in which the device elements are located, with sensors located in peripheral compartments, and sensor signal transmission means and controller are located in the central isolated compartment of the housing.

Images