Freezing insecticidal and disinfecting equipment with temperature, humidity and dew point linkage control

Abstract

The utility model discloses a freezing insecticidal disinfection equipment with temperature, humidity, dew point linkage control, including freezing room heat insulation box, gas measurement loop, conditioning gas supply loop and programmable logic controller, gas measurement loop has constant temperature measurement chamber and is installed with mirror dew point sensor in constant temperature measurement chamber inside, and constant temperature measurement chamber is communicated with the gas sampling port on freezing room heat insulation box through gas sampling pipeline, and the conditioning gas supply loop is provided with three -way proportional regulating valve and is communicated with conditioning gas backflow port through conditioning gas backflow pipeline, and programmable logic controller has signal connection with temperature sensing element, mirror dew point sensor and three -way proportional regulating valve respectively. The utility model discloses a gas sample is transferred to the dew point measurement of external constant temperature chamber, avoids the physical obstacle of sensor frost failure under low temperature environment, realizes accurate indirect measurement and closed loop regulation to the humidity in the box.

Description

Technical Field

[0001] This utility model relates to the technical field of cryogenic insecticidal and disinfection equipment, specifically to a cryogenic insecticidal and disinfection equipment with a structure for precise control of humidity in an ultra-low temperature environment. Background Technology

[0002] Cryogenic sterilization technology utilizes a low-temperature environment below -5°C to treat items, employing a physical method to kill pests, insect eggs, and some microorganisms. Due to its lack of chemical residues and material safety, it is widely used in the protective treatment of precious items such as archives, cultural relics, and textiles. In this process, relative humidity is a key parameter affecting the treatment effect and the safety of the items. Excessive humidity can lead to ice crystal damage, while excessively low humidity can cause the materials to dehydrate and become brittle. Therefore, maintaining the relative humidity in the freezer chamber within a preset range is a core technical requirement.

[0003] To achieve humidity monitoring, existing technologies typically involve directly installing capacitive or resistive humidity sensors inside the freezer. These sensors rely on the electrical characteristics of the humidity-sensitive element as humidity changes. However, in ultra-low temperature and high humidity environments ranging from -5°C to -40°C, frost inevitably forms on the surface of the sensor's sensitive element. The resulting frost layer completely alters the capacitance or resistance value of the element, leading to severe distortion or complete failure of the measurement signal. This renders the sensor's output data unreliable, which is an inherent physical defect of such sensors in low-temperature applications.

[0004] A search revealed that Chinese utility model patent CN112378963A discloses a humidity sensor with heating and temperature measurement functions and its manufacturing method. Although it attempts to control humidity in low-temperature environments, the humidity sensor is still built into the low-temperature chamber, which cannot fundamentally solve the problem of sensor frost failure at ultra-low temperatures, resulting in insufficient humidity control accuracy and long-term stability. Due to the inability to obtain accurate real-time humidity data, existing refrigeration equipment generally cannot form an effective closed-loop humidity control system, and can only rely on operator experience for rough open-loop adjustment. This control method has low accuracy, cannot meet the stringent processing requirements of high-end cultural relics, and poses a huge risk of damaging precious items due to uncontrolled humidity. Utility Model Content

[0005] The purpose of this invention is to provide a freezing insecticidal and disinfection device with temperature, humidity, and dew point linkage control. Through its unique structural design, it solves the problem that existing technologies cannot accurately detect and precisely control internal humidity in ultra-low temperature environments due to the failure of humidity sensors caused by frost formation.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A freezing insecticidal disinfection device with temperature, humidity, and dew point linkage control includes a freezer chamber with insulation, a gas measurement circuit, a conditioning gas supply circuit, and a programmable logic controller (PLC). An integrated temperature and humidity sensor probe is fixed to the inner wall of the freezer chamber with insulation. A gas sampling port and a conditioning gas return port are provided through the wall of the freezer chamber with insulation. The gas measurement circuit includes a constant temperature measurement chamber and a mirror-type dew point sensor. The constant temperature measurement chamber forms a fluid passage with the gas sampling port via a gas sampling pipeline. The mirror-type dew point sensor is housed inside the constant temperature measurement chamber. The conditioning gas supply circuit includes a three-way proportional control valve, which forms a fluid passage with the conditioning gas return port via a conditioning gas return pipeline. The signal input terminal of the PLC is electrically connected to the signal output terminals of the integrated temperature and humidity sensor probe and the mirror-type dew point sensor, respectively. The signal output terminal of the PLC is electrically connected to the signal input terminal of the three-way proportional control valve.

[0007] Preferably, the gas measurement circuit further includes a sampling inlet solenoid valve disposed on the gas sampling pipeline; and a measurement exhaust solenoid valve connected to the exhaust port of the constant temperature measurement chamber, wherein the signal output terminal of the programmable logic controller is electrically connected to the sampling inlet solenoid valve and the measurement exhaust solenoid valve respectively.

[0008] Preferably, the gas measurement circuit further includes a gas micro sampling pump disposed on the gas sampling pipeline, the gas micro sampling pump being located upstream of the sampling inlet solenoid valve, and the gas micro sampling pump being electrically connected to the programmable logic controller.

[0009] Preferably, the conditioning gas supply circuit further includes an oil-free silent air compressor, a refrigerated air dehumidifier and a high-pressure gas tank connected in series, and the outlet of the high-pressure gas tank is connected to the inlet of the three-way proportional regulating valve.

[0010] Preferably, the three-way proportional regulating valve has a first air inlet, a second air inlet, and a mixed air outlet. The first air inlet is connected to the outlet pipeline of the high-pressure gas storage tank, the second air inlet is connected to the external ambient atmosphere, and the mixed air outlet is connected to the conditioning gas return pipeline.

[0011] Preferably, it also includes a controlled atmosphere control cabinet; the gas measurement circuit, the conditioning gas supply circuit, and the programmable logic controller are all housed in the controlled atmosphere control cabinet, the freezer compartment insulation box is a structure independent of the controlled atmosphere control cabinet, and the gas sampling pipeline and the conditioning gas return pipeline pass through the wall panel of the controlled atmosphere control cabinet and are connected to the freezer compartment insulation box.

[0012] Preferably, it also includes a touch screen human-machine interface, which is electrically connected to the programmable logic controller, and its screen is divided into a target humidity value digital input area and a real-time data display area for temperature, humidity and dew point values.

[0013] Preferably, a Peltier thermoelectric cooler is attached to the outer wall of the constant temperature measurement chamber, and the Peltier thermoelectric cooler is electrically connected to the programmable logic controller.

[0014] Compared with the prior art, this utility model has the following advantages: This invention features an external constant-temperature measurement chamber independent of the cryogenic chamber, housing a high-precision mirror-type dew point sensor. Gas samples from the cryogenic chamber are extracted to this ambient-temperature measurement environment via a piping system for dew point measurement. This effectively avoids the physical problem of frost failure that any sensor would face when directly measuring inside a cryogenic chamber, ensuring the long-term, reliable, and high-precision acquisition of the fundamental humidity data source, namely the dew point value, thus laying a solid foundation for achieving precise closed-loop humidity control.

[0015] Each sensing and actuating component of this invention is electrically connected to a programmable logic controller (PLC) to form a complete hardware control loop. This structure can calculate the actual relative humidity in real time based on accurately measured temperature and dew point values ​​through the internal algorithm of the controller. After comparing the calculated relative humidity with the set value, it controls the opening of the three-way proportional regulating valve to precisely adjust the mixing ratio of dry air and ambient air. This allows for continuous, stable, and automated closed-loop regulation of the humidity in the freezer compartment, greatly improving the accuracy and reliability of environmental control and effectively ensuring the safety of the processed items. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall system structure of this utility model; Figure 2 This is a block diagram of the control system of this utility model; Figure 3 This is a schematic diagram of the conditioning gas supply circuit in this utility model.

[0017] In the diagram: 1-Refrigeration chamber insulation box; 2-Gas sampling port; 3-Cated gas reflux port; 4-Controlled atmosphere control cabinet; 5-Micro gas sampling pump; 6-Programmable logic controller; 7-Touch screen human-machine interface; 8-Mirror dew point sensor; 9-Constant temperature measurement chamber; 10-Sampling inlet solenoid valve; 11-Measurement exhaust solenoid valve; 12-Integrated temperature and humidity sensor probe; 13-Oil-free silent air compressor; 14-Refrigerated air dehumidifier; 15-High-pressure gas storage tank; 16-Cated gas reflux pipeline; 17-Three-way proportional control valve; 18-Gas sampling pipeline. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0019] Example 1 Please see Figure 1-3 As shown, this utility model provides a freezing insecticidal disinfection device with temperature, humidity and dew point linkage control, including two independent physical structural parts: a freezer insulated box 1 and a controlled atmosphere control cabinet 4.

[0020] The insulated freezer chamber 1 is a space for performing low-temperature treatment, and its walls are made of polyurethane insulated sandwich panels. An integrated temperature and humidity sensor probe 12 is fixedly installed on the inner wall of the freezer chamber 1. The integrated temperature and humidity sensor probe 12 has a built-in platinum resistance temperature sensing element. Two through interfaces are machined on the wall of the freezer chamber 1, namely a gas sampling port 2 and a conditioning gas return port 3.

[0021] The controlled atmosphere control cabinet 4 integrates the core measurement and control system of this equipment. A programmable logic controller 6 is installed inside the cabinet. The programmable logic controller 6 serves as the control center, and its various input and output ports are exposed for easy wiring. A touch screen human-machine interface 7 is embedded in the panel of the controlled atmosphere control cabinet 4. The data cable of the touch screen human-machine interface 7 is connected to the communication port of the programmable logic controller 6.

[0022] The main components of the gas measurement circuit are all located inside the gas control cabinet 4. The gas measurement circuit starts with the gas sampling pipeline 18, one end of which is connected to the gas sampling port 2 of the refrigeration chamber insulation box 1 via a quick-connect connector. Along the gas flow direction, the gas sampling pipeline 18 is connected in series with a gas micro sampling pump 5 and a sampling inlet solenoid valve 10, and then connected to the inlet of the constant temperature measurement chamber 9. The constant temperature measurement chamber 9 is a sealed container structure with a Peltier semiconductor cooling chip attached to its outer wall. The inner wall of the constant temperature measurement chamber 9 is also provided with a heating resistance wire, which together form a temperature maintenance structure. A high-precision mirror dew point sensor 8 is also installed inside the constant temperature measurement chamber 9. The exhaust port of the constant temperature measurement chamber 9 is connected to a measurement exhaust solenoid valve 11. The mirror dew point sensor 8, the sampling inlet solenoid valve 10, the measurement exhaust solenoid valve 11, the gas micro sampling pump 5, the Peltier element, and the heating wire are all electrically connected to the corresponding I / O port of the programmable logic controller 6 via wires.

[0023] The conditioning gas supply circuit is also integrated inside cabinet 4 of the conditioning control cabinet. The system is composed of an oil-free silent air compressor 13, a refrigerated air dehumidifier and dryer 14, and a high-pressure air tank 15 connected in series via a high-pressure air pipe. The outlet of the high-pressure air tank 15 is connected to the first air inlet of a three-way proportional control valve 17. The three-way proportional control valve 17 also has a second air inlet, which is directly connected to the outside atmosphere through a short pipe with a filter screen. The mixing outlet of the three-way proportional control valve 17 is connected to the conditioning gas return port 3 of the refrigeration chamber insulation box 1 through a conditioning gas return pipe 16. The proportional control signal terminal of the three-way proportional control valve 17 is electrically connected to the analog output port of the programmable logic controller 6.

[0024] Example 2 This embodiment has the same basic structure and connection relationship as Embodiment 1. The difference between the two lies in the construction of the conditioning gas supply circuit. In this embodiment, the conditioning gas supply circuit does not use the method of introducing ambient air, but instead constructs two gas sources with different humidity for mixing.

[0025] The specific structural design of the conditioning gas supply circuit in this embodiment differs from the previous one as follows: Two branch pipes are led out from the outlet of the high-pressure gas storage tank 15. The first branch pipe is directly connected to the first air inlet of the three-way proportional regulating valve 17 to supply deeply dry air. A miniature humidifier is connected in series on the second branch pipe, such as a water storage tank with a built-in breathable membrane. After the dry air flows through, it carries some water vapor to form humid air. The second branch pipe is connected to the second air inlet of the three-way proportional regulating valve 17. With this structural design, the three-way proportional regulating valve 17 mixes one dry air and one humid air. Compared with the direct introduction of ambient air with uncertain humidity in Embodiment 1, the structure of this embodiment can achieve a greater range and more stable adjustment of the humidity of the injected gas, which is especially suitable for application scenarios that require increased humidity, and further achieves better practical application results.

[0026] The above description is only a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the scope of protection of the present utility model.

Claims

1. A freezing insecticidal disinfection device with integrated temperature, humidity, and dew point control, characterized in that, The system includes a freezer insulation chamber (1), a gas measurement circuit, a conditioning gas supply circuit, and a programmable logic controller (6). An integrated temperature and humidity sensor probe (12) is fixed on the inner wall of the freezer insulation chamber (1). A gas sampling port (2) and a conditioning gas return port (3) are provided through the wall of the freezer insulation chamber (1). The gas measurement circuit includes a constant temperature measurement chamber (9) and a mirror dew point sensor (8). The constant temperature measurement chamber (9) forms a fluid passage with the gas sampling port (2) via a gas sampling pipeline (18). The mirror dew point sensor (8) The temperature measuring chamber (9) is contained inside the temperature measuring chamber. The conditioning gas supply circuit includes a three-way proportional regulating valve (17). The three-way proportional regulating valve (17) forms a fluid passage with the conditioning gas return port (3) via the conditioning gas return pipeline (16). The signal input terminal of the programmable logic controller (6) is electrically connected to the signal output terminal of the integrated temperature and humidity sensor probe (12) and the signal output terminal of the mirror dew point sensor (8). The signal output terminal of the programmable logic controller (6) is electrically connected to the signal input terminal of the three-way proportional regulating valve (17).

2. The freezing insecticidal disinfection equipment with temperature, humidity, and dew point linkage control as described in claim 1, characterized in that, The gas measurement circuit also includes a sampling inlet solenoid valve (10) and a measurement exhaust solenoid valve (11). The sampling inlet solenoid valve (10) is disposed on the gas sampling pipeline (18), and the measurement exhaust solenoid valve (11) is connected to the exhaust port of the constant temperature measurement chamber (9). The signal output terminal of the programmable logic controller (6) is also electrically connected to the sampling inlet solenoid valve (10) and the measurement exhaust solenoid valve (11) respectively.

3. The freezing insecticidal disinfection equipment with temperature, humidity, and dew point linkage control according to claim 2, characterized in that, The gas measurement circuit also includes a gas micro sampling pump (5) disposed on the gas sampling pipeline (18), the gas micro sampling pump (5) being located upstream of the sampling inlet solenoid valve (10), and the gas micro sampling pump (5) being electrically connected to the programmable logic controller (6).

4. The freezing insecticidal disinfection equipment with temperature, humidity, and dew point linkage control as described in claim 1, characterized in that, The conditioning gas supply circuit also includes an oil-free silent air compressor (13), a refrigerated air dehumidifier (14) and a high-pressure gas storage tank (15) connected in series; the outlet of the high-pressure gas storage tank (15) is connected to the inlet of the three-way proportional regulating valve (17).

5. A freezing insecticidal disinfection device with temperature, humidity, and dew point linkage control as described in claim 4, characterized in that, The three-way proportional control valve (17) has a first air inlet, a second air inlet and a mixed air outlet. The first air inlet is connected to the outlet pipeline of the high-pressure gas storage tank (15), the second air inlet is connected to the external ambient atmosphere, and the mixed air outlet is connected to the conditioning gas return pipeline (16).

6. The freezing insecticidal disinfection equipment with temperature, humidity, and dew point linkage control as described in claim 1, characterized in that, It also includes a controlled atmosphere control cabinet (4), in which the gas measurement circuit, the conditioning gas supply circuit and the programmable logic controller (6) are all housed. The freezer insulation box (1) is a structure independent of the controlled atmosphere control cabinet (4). The gas sampling pipeline (18) and the conditioning gas return pipeline (16) pass through the wall panel of the controlled atmosphere control cabinet (4) and are connected to the freezer insulation box (1).

7. A freezing insecticidal disinfection device with temperature, humidity, and dew point linkage control as described in claim 1, characterized in that, It also includes a touch screen human-machine interface (7), which is electrically connected to the programmable logic controller (6). The screen is divided into a target humidity value digital input area and a real-time data display area for temperature, humidity and dew point values.

8. A freezing insecticidal disinfection device with temperature, humidity, and dew point linkage control as described in claim 1, characterized in that, The constant temperature measurement chamber (9) is fitted with a Peltier semiconductor refrigeration chip on the outer side of its cavity wall, and the Peltier semiconductor refrigeration chip is electrically connected to the programmable logic controller (6).

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