Method and system for synergistically regulating radon concentration in radon chamber by temperature and humidity

Abstract

The application discloses a method and system for synergistically regulating radon concentration in a radon chamber by temperature and humidity, which comprises the following steps: firstly, fixing the temperature gradient to adjust the humidity to explore the competitive adsorption mechanism of water molecules; secondly, fixing the humidity gradient to regulate the temperature to analyze the temperature dependence; and finally, constructing a quadratic regression model to describe the radon concentration variation law under the combined action of temperature and humidity. The critical humidity threshold when the radon concentration reaches the peak value can be accurately identified and determined, the change trend of the radon concentration in different temperature and humidity intervals (such as the concentration fluctuation law under low temperature and high humidity or high temperature and low humidity) is clear, and the optimal temperature and humidity combination for maximizing the radon concentration can be calculated accordingly. The limitation of single variable regulation is effectively overcome, the fine synergistic control of the radon concentration is realized, and the steady-state performance and concentration controllability of the radon chamber are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of radon gas observation technology, specifically to a method and system for coordinating temperature and humidity control of radon concentration in a radon chamber. Background Technology

[0002] Radon is a naturally occurring radioactive inert gas widely found in soil, rocks, and groundwater. In fields such as radiation protection, environmental science, and nuclear physics experiments, establishing highly stable and precisely controllable radon chambers is crucial for measuring radon release rates, calibrating low-background detection, and studying biological effects. Existing radon chamber construction methods primarily rely on radium source decay or groundwater bubbling degassing to generate radon. Among these methods, using a bubbling degassing device to release radon from groundwater into a sealed container is a common technique for establishing non-radium source steady-state radon chamber systems. Its advantages include not requiring long-half-life radioactive isotope sources, relatively safe operation, and ease of rapid steady-state establishment.

[0003] However, existing technologies face significant technical challenges in practical applications: current radon chamber systems typically focus only on single-function temperature control or coarse-grained humidity management, lacking in-depth research into the synergistic effects of temperature and humidity. Specifically, the radon release behavior on the chamber walls and its diffusion process in the air are greatly influenced by ambient temperature and humidity. On the one hand, excessively high relative humidity leads to competitive adsorption of water molecules on the material surface, forming a liquid water film, increasing the viscous resistance to gas diffusion, and thus inhibiting the surface release rate of radon. On the other hand, temperature changes alter the Henry's law coefficient, which in turn nonlinearly affects the distribution equilibrium of radon at the gas-liquid interface. Existing technologies often fail to quantify this complex nonlinear coupling relationship, making it difficult to obtain stable and optimal radon concentration levels under specific environmental conditions, and thus failing to meet the stringent requirements for radon concentration constancy in high-precision experiments. Summary of the Invention

[0004] This invention aims to provide a method and system for synergistic temperature and humidity control of radon concentration in a radon chamber, which effectively overcomes the limitations of single-variable control, achieves refined synergistic control of radon concentration, and significantly improves the steady-state performance and concentration controllability of the radon chamber.

[0005] To achieve the above objectives, the technical solution adopted by this invention is: a method for synergistically regulating radon concentration in a radon chamber using temperature and humidity, comprising:

[0006] S1. Radon gas from the groundwater is extracted and injected into the radon chamber through a bubbling degassing device to establish a non-radium source steady-state radon chamber system.

[0007] S2. In the non-radium source steady-state radon chamber system, the internal temperature of the radon chamber is kept constant, and the relative humidity is adjusted by gradient through humidification or dehumidification equipment to explore the inhibitory effect of water molecule competitive adsorption on the radon surface release rate and the gas diffusion viscosity resistance mechanism, and to obtain data on the change of radon concentration with humidity.

[0008] S3. Based on the data on the change of radon concentration with humidity, determine the critical humidity threshold when the radon concentration reaches its peak, wherein the critical humidity threshold is 40%-50%RH;

[0009] S4. In the non-radium source steady-state radon chamber system, the relative humidity inside the radon chamber is kept constant, and the temperature is adjusted stepwise by a temperature control device to analyze the nonlinear relationship between the temperature-dependent Henry coefficient and the radon concentration change.

[0010] S5. Based on the determined critical humidity threshold and the analyzed temperature dependence, construct a quadratic regression model to describe the radon concentration change law under the combined effect of temperature and humidity, and calculate the optimal temperature and humidity combination corresponding to the extreme point of radon concentration based on the quadratic regression model.

[0011] Preferably, in S2, the process of gradient adjustment of relative humidity includes maintaining the relative humidity in the radon chamber at 30%RH, 40%RH, 50%RH, 60%RH, 70%RH and 80%RH respectively, and measuring the change of radon concentration in the radon chamber at each humidity level.

[0012] Preferably, in S4, the process of step-by-step temperature control includes adjusting the temperature in the radon chamber to 25°C, 27°C, 29°C, 31°C, 33°C and 35°C respectively, and measuring the change in radon concentration in the radon chamber at each temperature level.

[0013] Preferably, in S5, the expression for the quadratic regression model is: Where C represents radon concentration, T represents temperature, and H represents relative humidity. to is the regression coefficient.

[0014] Preferably, in S5, when the relative humidity is below 50%RH, the radon concentration shows an increasing trend with increasing temperature; when the relative humidity is above 60%RH, the radon concentration shows a decreasing trend with increasing temperature.

[0015] Preferably, in S5, the process of calculating the optimal temperature and humidity combination corresponding to the extreme point of radon concentration includes: taking the partial derivatives of the quadratic regression model with respect to temperature and humidity respectively, setting the partial derivatives to zero, and solving for the temperature at which the radon concentration is maximum as 28°C and the relative humidity as 45%.

[0016] On the other hand, this invention proposes a system for synergistic temperature and humidity control of radon concentration in a radon chamber, comprising:

[0017] The radon gas generating module is configured to extract radon gas from groundwater through a bubbling degassing device and inject it into the radon chamber to establish a non-radium source steady-state radon chamber system.

[0018] The environmental control module is configured to perform constant temperature and humidity control and constant humidity and temperature control operations respectively in the non-radium source steady-state radon chamber system, wherein the constant temperature and humidity control is used to gradient adjust the relative humidity, and the constant humidity and temperature control is used to stepwise adjust the temperature.

[0019] The data acquisition module is configured to monitor and record radon concentration, temperature, and humidity data in the radon chamber in real time.

[0020] The data processing module is configured to build a quadratic regression model based on the collected data and calculate the optimal temperature and humidity combination corresponding to the extreme point of radon concentration.

[0021] The control feedback module is configured to adjust the operating parameters of the environmental control module according to the optimal temperature and humidity combination, so as to achieve coordinated control of radon concentration.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention first uses a fixed temperature gradient to adjust humidity to explore the competitive adsorption mechanism of water molecules, then uses a fixed humidity gradient to control temperature to analyze the temperature dependence, and finally constructs a quadratic regression model to describe the radon concentration variation law under the combined effect of temperature and humidity. It can accurately identify and determine the critical humidity threshold when the radon concentration reaches its peak, clarify the radon concentration variation trend under different temperature and humidity ranges (such as the concentration fluctuation law under low temperature and high humidity or high temperature and low humidity), and calculate the optimal temperature and humidity combination to maximize the radon concentration. It effectively overcomes the limitations of single variable control, realizes the refined and coordinated control of radon concentration, and significantly improves the steady-state performance and concentration controllability of the radon chamber. Attached Figure Description

[0024] Figure 1 The graph shows the radon concentration (30%RH) measured at different temperatures according to the present invention.

[0025] Figure 2 The graph shows the radon concentration (40%RH) measured at different temperatures according to the present invention.

[0026] Figure 3 The graph shows the radon concentration (50%RH) measured at different temperatures according to the present invention.

[0027] Figure 4 The graph shows the radon concentration (60%RH) measured at different temperatures according to the present invention.

[0028] Figure 5The graph shows the radon concentration (70%RH) measured at different temperatures according to the present invention.

[0029] Figure 6 The graph shows the radon concentration (25°C) measured under different humidity conditions according to the present invention.

[0030] Figure 7 This is a graph showing the real-time monitoring curves (25°C) of radon concentration and relative humidity according to the present invention.

[0031] Figure 8 This is a 3D waterfall diagram (25°C) showing the changes in radon concentration, humidity, and temperature over time according to the present invention.

[0032] Figure 9 The graph shows the radon concentration (27°C) measured under different humidity conditions according to the present invention.

[0033] Figure 10 This is a graph showing the real-time monitoring curves (27°C) of radon concentration and relative humidity according to the present invention.

[0034] Figure 11 This is a 3D waterfall diagram (27°C) showing the changes in radon concentration, humidity, and temperature over time according to the present invention.

[0035] Figure 12 This is a graph showing the radon concentration curves (29°C) obtained under different humidity conditions according to the present invention.

[0036] Figure 13 This is a graph showing the real-time monitoring curves (29°C) of radon concentration and relative humidity according to the present invention.

[0037] Figure 14 This is a 3D waterfall diagram (29°C) showing the changes in radon concentration, humidity, and temperature over time according to the present invention.

[0038] Figure 15 The graph shows the radon concentration (31°C) measured under different humidity conditions according to the present invention.

[0039] Figure 16 This is a graph showing the real-time monitoring curves (31°C) of radon concentration and relative humidity according to the present invention.

[0040] Figure 17 This is a 3D waterfall diagram (31°C) showing the changes in radon concentration, humidity, and temperature over time according to the present invention.

[0041] Figure 18 The graph shows the radon concentration (33°C) measured under different humidity conditions according to the present invention.

[0042] Figure 19 This is a graph showing the real-time monitoring curves (33°C) of radon concentration and relative humidity according to the present invention.

[0043] Figure 20 This is a 3D waterfall diagram (33°C) showing the changes in radon concentration, humidity, and temperature over time according to the present invention.

[0044] Figure 21 The graph shows the radon concentration (35°C) measured under different humidity levels according to the present invention.

[0045] Figure 22 This is a graph showing the real-time monitoring curves (35°C) of radon concentration and relative humidity according to the present invention.

[0046] Figure 23 This is a 3D waterfall diagram (35°C) showing the changes in radon concentration, humidity, and temperature over time according to the present invention.

[0047] Figure 24 This is a 3D response surface and contour plot of the effect of temperature and relative humidity on radon concentration in a radon chamber according to the present invention.

[0048] Figure 25 The heat map and contour map showing the distribution of radon concentration with temperature and humidity according to the present invention;

[0049] Figure 26 The heat map and contour map showing the distribution of radon concentration with temperature and humidity according to the present invention;

[0050] Figure 27 This is a graph showing the variation trend of radon concentration with relative humidity under different temperature conditions according to the present invention.

[0051] Figure 28 This is a 3D response surface and contour plot of the effect of temperature and relative humidity on radon concentration in a radon chamber according to the present invention.

[0052] Figure 29 This is a 3D response surface and contour plot of the effect of temperature and relative humidity on radon concentration in a radon chamber according to the present invention.

[0053] Figure 30 The flowchart shows the method for synergistic temperature and humidity control of radon concentration in a radon chamber according to the present invention.

[0054] Figure 31 This is a block diagram of the non-radium source steady-state radon chamber of the present invention;

[0055] Figure 32 This is a schematic diagram of the bubbling system of the present invention. Detailed Implementation

[0056] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0057] like Figure 30As shown, this invention proposes a method for synergistically regulating radon concentration in a radon chamber using temperature and humidity, comprising:

[0058] S1. Radon gas from the groundwater is extracted and injected into the radon chamber through a bubbling degassing device to establish a non-radium source steady-state radon chamber system.

[0059] S2. In the non-radium source steady-state radon chamber system, the internal temperature of the radon chamber is kept constant, and the relative humidity is adjusted by gradient through humidification or dehumidification equipment to explore the inhibitory effect of water molecule competitive adsorption on the radon surface release rate and the gas diffusion viscosity resistance mechanism, and to obtain data on the change of radon concentration with humidity.

[0060] The process of gradient adjustment of relative humidity includes maintaining the relative humidity in the radon chamber at 30%RH, 40%RH, 50%RH, 60%RH, 70%RH and 80%RH respectively, and measuring the change of radon concentration in the radon chamber at each humidity level.

[0061] S3. Based on the data on the change of radon concentration with humidity, determine the critical humidity threshold when the radon concentration reaches its peak, wherein the critical humidity threshold is 40%-50%RH;

[0062] S4. In the non-radium source steady-state radon chamber system, the relative humidity inside the radon chamber is kept constant, and the temperature is adjusted stepwise by a temperature control device to analyze the nonlinear relationship between the temperature-dependent Henry coefficient and the radon concentration change.

[0063] The stepwise temperature control process involves adjusting the temperature inside the radon chamber to 25℃, 27℃, 29℃, 31℃, 33℃ and 35℃ respectively, and measuring the change in radon concentration inside the chamber at each temperature level.

[0064] S5. Based on the determined critical humidity threshold and the analyzed temperature dependence, construct a quadratic regression model to describe the radon concentration change law under the combined effect of temperature and humidity, and calculate the optimal temperature and humidity combination corresponding to the extreme point of radon concentration based on the quadratic regression model.

[0065] Specifically, the expression for the quadratic regression model is: Where C represents radon concentration, T represents temperature, and H represents relative humidity. to is the regression coefficient.

[0066] When the relative humidity is below 50%RH, the radon concentration increases with rising temperature; when the relative humidity is above 60%RH, the radon concentration decreases with rising temperature.

[0067] Furthermore, the process of calculating the optimal temperature and humidity combination corresponding to the extreme point of radon concentration includes: taking the partial derivatives of the quadratic regression model with respect to temperature and humidity respectively, setting the partial derivatives to zero, and solving for the temperature at which the radon concentration is maximum at 28℃ and the relative humidity at 45%.

[0068] On the other hand, this invention proposes a system for synergistic temperature and humidity control of radon concentration in a radon chamber, such as... Figures 31-32 As shown, it includes:

[0069] The radon gas generating module is configured to extract radon gas from groundwater through a bubbling degassing device and inject it into the radon chamber to establish a non-radium source steady-state radon chamber system.

[0070] The environmental control module is configured to perform constant temperature and humidity control and constant humidity and temperature control operations respectively in the non-radium source steady-state radon chamber system, wherein the constant temperature and humidity control is used to gradient adjust the relative humidity, and the constant humidity and temperature control is used to stepwise adjust the temperature.

[0071] The data acquisition module is configured to monitor and record radon concentration, temperature, and humidity data in the radon chamber in real time.

[0072] The data processing module is configured to build a quadratic regression model based on the collected data and calculate the optimal temperature and humidity combination corresponding to the extreme point of radon concentration.

[0073] The control feedback module is configured to adjust the operating parameters of the environmental control module according to the optimal temperature and humidity combination, so as to achieve coordinated control of radon concentration.

[0074] The relationship between temperature, humidity, and radon concentration is detailed below with reference to the attached diagram:

[0075] Figure 1 (a) The radon concentration in the radon chamber was measured while maintaining a humidity of 30%RH and adjusting the temperature (25, 27, 29, 31, 33, and 35°C). The blue hollow circles represent the raw measurement data, and the red solid line represents the smoothed trend line. The trend line shows that the radon concentration in the chamber gradually increases with increasing temperature.

[0076] Figure 1 (b) shows the variation of radon concentration in the radon chamber with temperature. In the low-temperature range (25-29℃), the increase in radon concentration is not significant, with an increase of 1.49%. In the medium-temperature range (29-33℃), the radon concentration increases by 5.07%. In the high-temperature range (33-35℃), the radon concentration decreases by 3.74%. Among the three temperature stages, the medium-temperature range is a period of rapid increase, while the high-temperature range is a period of saturation and slowdown.

[0077] Figure 2(a) The changes in radon concentration in the radon chamber were measured while maintaining a humidity of 40%RH and adjusting the temperature (25, 27, 29, 31, 33, and 35°C). The blue hollow circles represent the raw measurement data, and the red solid line represents the smoothed trend line. Compared to the radon concentration change at 30%RH, at 40%RH, the radon concentration initially increased and then gradually decreased with increasing temperature.

[0078] Figure 2 (b) shows that radon concentration increased by 4.66% when the temperature rose from 25°C to 27°C; increased by 0.99% when the temperature rose from 27°C to 29°C; decreased by 1.47% when the temperature rose from 29°C to 31°C; decreased by 4.48% when the temperature rose from 31°C to 33°C; and decreased by 2.08% when the temperature rose from 33°C to 35°C.

[0079] Figure 3 (a) shows the changes in radon concentration in a radon chamber maintained at 50% RH, with adjusted temperatures (25, 27, 29, 31, 33, and 35°C). The blue hollow circles represent the raw measurement data, and the red solid line represents the smoothed trend line. Judging from the trend line, this group shows that the radon concentration gradually increases with increasing temperature, then reaches a stable concentration and hardly changes further.

[0080] Figure 3 (b) The results show that as the temperature rises from 25°C to 27°C, the radon concentration increases by 3.5%; from 27°C to 29°C, it increases by 4.3%; from 29°C to 31°C, it increases by 8.4%; from 31°C to 33°C, it increases by 0.43%; and from 33°C to 35°C, it decreases by 0.85%. The overall trend remains a unidirectional increase in radon concentration with increasing temperature. Furthermore, the 8.4% increase in radon concentration from 29°C to 31°C indicates that this temperature range represents a sensitive threshold window for radon concentration. The 0.85% decrease in radon concentration from 33°C to 35°C suggests that the radon migration effect may be caused by humidity changes under high-temperature conditions.

[0081] Figure 4 (a) shows the changes in radon concentration in a radon chamber maintained at 60% RH, with adjusted temperatures (25, 27, 29, 31, 33, and 35°C). The blue hollow circles represent the raw measurement data, and the red solid line represents the smoothed trend line. Judging from the trend line, this group is characterized by minimal changes in radon concentration with increasing temperature; the overall trend is an initial increase, followed by a decrease, and finally a return to stability.

[0082] Figure 4(b) The data shows that as the temperature increased from 25°C to 27°C, the radon concentration increased by 1.57%; from 27°C to 29°C, the radon concentration decreased by 2.58%; from 29°C to 31°C, the radon concentration decreased by 1.06%; from 31°C to 33°C, the radon concentration decreased by 2.67%; and from 33°C to 35°C, the radon concentration decreased by 1.65%. Except for the increase from 25°C to 27°C, the radon concentration decreased slightly in other phases. The largest decrease occurred from 27°C to 29°C. This data shows a continuous decrease in radon concentration, which first excludes the system response of non-radium source radon chambers, because the radon source was maintained at a stable concentration of 112 Bq / L throughout the experiment.

[0083] Figure 5 (a) The changes in radon concentration in the radon chamber were measured while maintaining a humidity of 70%RH and adjusting the temperature (25, 27, 29, 31, 33, and 35°C). The blue hollow circles represent the raw measurement data, and the red solid line represents the smoothed trend line. The trend line shows that the radon concentration changes very little with increasing temperature, exhibiting a slight overall downward trend.

[0084] Figure 5 (b) This study shows that as the temperature increased from 25°C to 27°C, the radon concentration decreased by 1.69%; from 27°C to 29°C, the radon concentration decreased by 1.71%; from 29°C to 31°C, the radon concentration decreased by 1.16%; from 31°C to 33°C, the radon concentration decreased by 2.94%; and from 33°C to 35°C, the radon concentration decreased by 1.21%. The magnitude of radon concentration changes across these temperature ranges indicates a negative correlation between radon concentration and temperature. Under the conditions of this study, the humidity reached 70% RH, which most likely dominated the changes in radon concentration. This is because in high humidity environments, the number of water molecules on the aerosol surface increases, leading to a greater loss of alpha particle decay energy emitted by radon, thereby inhibiting radon adsorption and diffusion.

[0085] like Figure 6As shown, the radon chamber temperature was fixed at 25℃. Radon concentration was measured by adjusting the humidity inside the chamber (30%, 40%, 50%, 60%, 70%, and 80%RH). The blue hollow scatter dots in the graph represent the raw measured data; the red solid line represents the trend of radon concentration after smoothing. The graph clearly shows the effect of humidity changes on radon concentration. As humidity increases, radon concentration gradually increases. The radon concentration reaches its maximum at 50%RH; when humidity increases to 60%RH, the radon concentration drops sharply, then increases slowly again with further increases in humidity. From the trend of radon concentration changes, there may be a threshold, where drastic changes in radon concentration may occur when humidity exceeds a certain critical point. For example, in the graph, the change exceeds 70% when humidity reaches 60%RH. When humidity rises to 70%RH, the change in radon concentration also reaches 60%. However, when humidity increases from 40%RH to 50%RH, the change in radon concentration is very small. The changes in radon concentration in the two humidity ranges above indicate that there is likely a threshold point for the effect of humidity on radon concentration.

[0086] To more clearly illustrate the relationship between humidity changes and radon concentration, through... Figure 7 The graph illustrates the trend changes of radon concentration and humidity. The blue hollow circles represent the raw radon concentration data; the red solid line represents the smoothed radon concentration curve; and the green hollow squares represent the humidity inside the radon-containing room. The graph clearly shows a significant synchronicity between changes in humidity and radon concentration within the radon-containing room. In particular, the red rectangular area in the graph demonstrates a clear correlation between radon concentration and humidity changes.

[0087] To further determine whether other factors influence radon concentration, the indoor radon concentration measurements, humidity, and temperature were plotted as a 3D waterfall diagram. For example... Figure 8 As shown in the figure, the blue curve represents the original measurement data; the red curve represents the radon concentration trend after smoothing; the green curve represents the humidity change in the radon chamber; and the orange curve represents the temperature change in the radon chamber. Figure 8 This indicates that the overall trend of radon concentration changes is consistent with the humidity changes inside the radon chamber, and the temperature inside the radon chamber remains basically stable.

[0088] like Figure 9 As shown, the radon chamber temperature was fixed at 27℃, and the radon concentration was measured by adjusting the humidity inside the chamber. The blue hollow circles in the figure represent the raw measured data; the red solid line represents the trend of radon concentration after smoothing. Figure 9The results show that as humidity increases from 30% to 50% RH, radon concentration gradually increases. When humidity reaches 60% RH, radon concentration decreases significantly. When humidity continues to increase to 70% RH, radon concentration continues to show a significant decrease. When humidity increases to 80% RH, radon concentration shows a slight increase again. The trend curve of humidity change on radon concentration remains consistent under conditions of 25℃ and 27℃, that is, within the 30-50% RH range, radon concentration gradually increases; when humidity reaches 60% RH, radon concentration decreases significantly; when humidity exceeds 70% RH, radon concentration increases slightly again.

[0089] Figure 10 This diagram illustrates the characteristics of radon concentration changes with humidity. The blue hollow circles represent the raw radon concentration data; the red solid line represents the smoothed radon concentration curve; and the green hollow squares represent the humidity inside the radon-containing room. As humidity gradually increases, the radon concentration also gradually increases; however, when the humidity reaches a certain point, the radon concentration suddenly drops sharply. This is clearly demonstrated in the red rectangular area of ​​the diagram.

[0090] like Figure 11 A 3D waterfall plot is created to represent the radon concentration measurement results, humidity, and temperature inside the radon chamber. The blue curve represents the original measurement data; the red curve represents the smoothed radon concentration trend; the green curve represents the humidity change inside the radon chamber; and the orange curve represents the temperature change inside the radon chamber. Figure 11 The results show that the temperature inside the radon chamber remained stable, and the gradually increasing humidity corresponded to a change in radon concentration that first rose, then fell, and finally rose again. This indicates that under the established research conditions, humidity has a significant impact on radon concentration changes.

[0091] Figure 12 The graph shows the radon concentration changes caused by humidity variations within a radon chamber at a temperature of 29°C. The blue hollow circles represent the raw data, while the red solid line represents the trend of radon concentration after smoothing. A key characteristic of the red solid line trend is that the radon concentration decreases significantly when the humidity reaches 60% RH, and this decrease continues until the humidity reaches 70% RH. When the humidity reaches 80% RH, the radon concentration stops decreasing, which is consistent with the trends observed at 25°C and 27°C.

[0092] like Figure 13 This diagram illustrates the trend changes in both humidity and radon concentration. The blue hollow circles represent the raw radon concentration data; the red solid line represents the smoothed radon concentration curve; and the green hollow squares represent the humidity inside the radon-containing room. The red rectangular area in the diagram demonstrates the significant effect of increased humidity on radon concentration suppression.

[0093] like Figure 14A 3D waterfall plot was created to represent the radon concentration measurement results, humidity, and temperature. The blue curve represents the original measurement data; the red curve represents the smoothed radon concentration trend; the green curve represents humidity changes within the radon chamber; and the orange curve represents temperature changes within the radon chamber. The plot clearly shows that under the set temperature conditions, only humidity and radon concentration change, while the temperature remains stable. The measurement results indicate that: 1. The influence of humidity is not negligible; 2. The effect of humidity changes on radon concentration may not be singular, but rather has a threshold point.

[0094] Figure 15 The graph shows the changes in humidity and radon concentration inside a radon chamber at a temperature of 31°C. The blue hollow circles represent the raw data; the red solid line represents the trend of radon radioactivity concentration after smoothing. The trend of the red solid line is as follows: when the humidity inside the radon chamber reaches 50% RH, the radon concentration reaches its maximum; in the 60-70% RH range, the radon concentration continues to decrease; and at 80% RH, the radon concentration stops decreasing. The overall change in radon concentration is relatively gradual, without drastic changes, especially in the 60-70% RH range.

[0095] like Figure 16 This displays the trend changes of both humidity and radon concentration. The blue hollow circles represent the original radon concentration data; the red solid line represents the smoothed radon concentration curve; and the green hollow squares represent the humidity in the radon-containing room.

[0096] Figure 17 A 3D waterfall plot was created to show the radon concentration measurements, humidity, and temperature. The blue curve represents the original measurement data; the red curve represents the smoothed radon concentration trend; the green curve represents humidity changes within the radon chamber; and the orange curve represents temperature changes within the radon chamber. The plot shows that the temperature within the radon chamber remained stable during the measurement period.

[0097] Figure 18 Yes, the changes in humidity and radon concentration in the radon chamber were measured at a temperature of 33℃. The blue hollow circles in the graph represent the raw data; the red solid line represents the trend of radon radioactivity concentration after smoothing. The trend of radon concentration change shown by the red solid line generally maintains the characteristic of first rising, then falling, and then rising again. The radon concentration reaches its maximum when the indoor humidity reaches 50%RH; in the 60-70%RH range, the radon concentration continues to decrease; at 80%RH, the radon concentration stops decreasing. However, unlike before, in the radon chamber, with the temperature maintained at 33℃, when the humidity increases to 60%RH, the decrease in radon concentration is not as significant as before; instead, the decrease in radon concentration is most pronounced when the humidity reaches 80%RH.

[0098] Figure 19The graph illustrates the trends in radon concentration and humidity. Blue hollow circles represent the raw radon concentration data; the red solid line represents the smoothed radon concentration curve; and green hollow squares represent the humidity within the radon-containing chamber. The graph visually demonstrates the overall trend of radon concentration first increasing and then decreasing with increasing humidity. Furthermore, within the red, blue, and gray rectangular areas, both radon concentration and humidity decreased simultaneously.

[0099] Figure 20 This is a 3D waterfall plot created by combining radon concentration measurements, humidity, and temperature. The blue curve represents the original measurement data; the red curve represents the smoothed radon concentration trend; the green curve represents humidity changes within the radon chamber; and the orange curve represents temperature changes within the radon chamber. Overall, the radon chamber temperature remained stable, while the humidity gradually increased, and the radon concentration initially increased and then decreased.

[0100] Figure 21 As shown, the radon chamber temperature was fixed at 35℃, and the radon concentration was measured by adjusting the humidity inside the chamber. The blue hollow scatter dots in the figure represent the raw measured data; the red solid line represents the trend of concentration change after smoothing. In the figure, the radon concentration reaches its maximum when the humidity reaches 60%RH; when it reaches 70%RH, the radon concentration decreases and continues until 80%RH. With increasing humidity, the trend of radon concentration change is still initially increasing and then decreasing. Compared with the radon concentration changes at other temperatures, at 35℃, the radon concentration gradually increases when the humidity is between 30-60%RH; when the humidity is between 70-80%RH, the radon concentration shows a decreasing trend. The fluctuations in radon concentration in the 70%RH and 80%RH ranges in the figure are due to a power outage in the radon chamber. To avoid abnormal and unstable radon measurement values ​​caused by instrument malfunction, the measurement cycle was increased.

[0101] The trend changes in humidity and concentration are as follows: Figure 22 As shown in the figure, the blue hollow circles represent the original radon concentration data; the red solid line represents the smoothed radon concentration curve; and the green hollow squares represent the humidity inside the radon chamber. The red rectangular area in the figure clearly illustrates the characteristic of increasing humidity and decreasing radon concentration.

[0102] Figure 23 This is a 3D waterfall plot composed of radon concentration measurement results, humidity, and temperature within the radon chamber. The blue curve represents the original measurement data; the red curve represents the smoothed radon concentration trend; the green curve represents humidity changes within the radon chamber; and the orange curve represents temperature changes. The plot shows that the temperature within the radon chamber remained stable, while humidity changes significantly affected radon concentration. Under high humidity conditions, radon concentrations decreased at all temperatures, consistent with test results indicating a significant decrease in activated carbon adsorption capacity under high humidity conditions.

[0103] The effect of temperature on radon concentration changes is as follows:

[0104] Figure 24 The effects of temperature on radon concentration are not monotonic. For example, at 50% RH, the effect of temperature on radon concentration exhibits a complex pattern of first increasing, then decreasing, then increasing again and decreasing again. Furthermore, research on activated carbon adsorption of radon suggests that at extremely low temperatures, the adsorption coefficient of activated carbon is far greater than that at room temperature.

[0105] A quadratic regression model was established to describe the variation of radon concentration under the combined effects of humidity and temperature. A multiple linear model containing quadratic and interaction terms was adopted:

[0106] (1)

[0107] In formula (1), :intercept; Linear effect coefficient; : Coefficient of the quadratic term; : Interaction coefficient. Using Python for multiple regression, we have:

[0108] (2)

[0109] Formula (2), R 2 =0.914, indicating a good fit; RMSE=0.63Bq / L indicates high accuracy.

[0110] The vertex of the humidity parabola is:

[0111] (3)

[0112] The vertex of the temperature parabola is:

[0113] (4)

[0114] The gradient of the effect of temperature on radon concentration:

[0115] (5)

[0116] When the humidity H = 30% and 70%, substituting into equation (5) respectively, we get 0.18 Bq / (L·℃) and -0.23 Bq / (L·℃).

[0117] Figure 25 The results showed that when the humidity was 30-50%RH, the radon concentration in the radon chamber showed a significant upward trend, i.e., the initial upward phase; when the humidity reached 50%RH, the radon concentration in the radon chamber reached its maximum value, i.e., the dynamic equilibrium phase; and when the humidity was 60-70%RH, the radon concentration in the radon chamber showed a significant downward trend, i.e., the later downward phase.

[0118] Because the adsorption of radon atoms on the walls or gas source surfaces of the radon chamber is primarily physical adsorption, and water molecules, being polar molecules, have a much stronger adsorption capacity than non-polar radon atoms, one explanation for the initial rise is that as humidity increases from a low level, water vapor molecules in the air preemptively occupy the active sites on the solid surface, displacing the radon atoms originally adsorbed in the walls or pores of the medium—a displacement process. The result is a large amount of radon moving from the solid phase into the gas phase, leading to a significant increase in the radon concentration in the air within the radon chamber.

[0119] At a humidity of around 50% RH, the coverage of adsorption sites by water molecules reaches the edge of saturation, at which point the radon release rate reaches its highest point. At this time, the increase in temperature further intensifies the Brownian motion of molecules, resulting in the global highest value (23.5 Bq / L) in experimental data when 50% RH is combined with high water temperature (e.g., 33-35℃).

[0120] During the later stages of descent, when humidity continues to rise above a critical value, the physical state of water molecules changes. Several reasons may be at play: First, under high humidity, condensation occurs in the micropores of the solid surface, forming a liquid water film. Although radon atoms are poorly soluble in water, the liquid water film creates a physical barrier, increasing the resistance to radon diffusion from the material's interior into space (capillary condensation and physical barrier). Second, although radon has low solubility, some radon dissolves in the tiny droplets (aerosols) formed under high humidity and settles onto the container wall, leading to a decrease in radon concentration in the gas phase (dissolution and aerosol sedimentation). Third, the molecular weight of water vapor (18) is less than the average molecular weight of air (29), and high humidity alters the kinematic viscosity of the mixed gas, potentially affecting the uniform distribution of radon under indoor fan circulation.

[0121] The indoor radon concentration variation pattern is as follows:

[0122] 1) Capillary condensation and physical barrier

[0123] The study by Perrier et al. discussed how relative humidity exceeding 70% triggers effective water vapor condensation, leading to an abnormal decrease in radon signal, which supports the mechanism of capillary condensation forming a barrier.

[0124] 2) Dissolution and aerosol sedimentation

[0125] Although radon is an inert gas, in high humidity environments, the aggregation of water molecules can scavenge radon and its decay products.

[0126] 3) Air density and dynamic viscosity

[0127] In addition to the adsorption mechanism, changes in the physical properties of mixed gases under high humidity conditions may also interfere with the spatiotemporal uniformity of concentration distribution.

[0128] The concentration of radon in a radon chamber exhibits a significant threshold effect due to humidity. Below 50% RH, competitive adsorption by water molecules dominates, acting as a promoter; above 60% RH, capillary filling and liquid film barrier effects of water molecules dominate, acting as an inhibitor. Increased temperature plays a dual role in accelerating diffusion and altering saturation pressure across different humidity ranges, leading to the formation of maxima regions on the 3D surface. Initially, as moisture increases, the release rate increases due to the replacement of radon adsorbed on the pore surface (adsorption competition); however, as further moisture increases, filling the micropores with liquid water, diffusion is hindered, and the release rate decreases.

[0129] The mechanism by which key parameters affect radon concentration is as follows:

[0130] 1) Density of moist air ( )

[0131] According to the ideal gas equation:

[0132] (6)

[0133] In formula (6), :pressure; :volume; Thermodynamic temperature; : Amount of substance; : Universal gas constant, 8.314 J / (mol·K).

[0134] And because, Therefore, we have:

[0135] (7)

[0136] (8)

[0137] Therefore, the gas constant is defined as follows:

[0138] (9)

[0139] According to the law of partial pressures in the ideal gas law, the density of moist air is the sum of the partial pressure of dry air and the partial pressure of water vapor:

[0140] (10)

[0141] (11)

[0142] (12)

[0143] In formula (12), ρ mix Density of mixed gas, kg / m³3 ;P d Partial pressure of dry air; P v Water vapor partial pressure, which is affected by relative humidity, P d =RH P sa (T), where P sa It is the saturated vapor pressure at the current humidity level. The higher the humidity, the higher the vapor pressure. d The larger; R d : Specific gas constant of dry air; R v : Specific gas constant of moist air; T: Thermodynamic temperature.

[0144] Because water molecules are lighter than air molecules, At the same temperature and total pressure, as humidity increases, Increase Decrease Significant decrease.

[0145] 2) Dynamic viscosity ( )

[0146] The dynamic viscosity of a gas is mainly affected by temperature, but in gas mixtures, the Wilke equation should be consulted:

[0147] (13)

[0148] For a binary mixture like humid air (dry air + water vapor), the formula expands to:

[0149] (14)

[0150] In formula (13), , Components and mole fraction; , Components and The dynamic viscosity in its pure state; Interaction parameters, representing components For components The influence of momentum transfer on resistance.

[0151] (15)

[0152] In formula (15), , : Molar mass of each component.

[0153] Equation (15) shows that as humidity increases, the dynamic viscosity of the gas mixture increases. In reality, it's a slight decrease.

[0154] In Wilke's formula, the mixed viscosity depends on the pure viscosity of each component. At room temperature, such as 20°C, the dynamic viscosity of dry air is... It is 18.2 10 -6 Pa s, the dynamic viscosity of water vapor It is 9.7 10 -6 Pa This indicates that the dynamic viscosity of water vapor is only about half that of dry air, meaning that water vapor acts as a lubricant or diluent in the gas mixture.

[0155] According to formula (13), as humidity increases, the mole fraction rise, Decrease. For the dry air term, the denominator... It increases with increasing humidity, and because The decrease in this term is relatively large, and its impact on the overall effect is very significant. For the water vapor term, although... Increased, but due to The increase itself is very small, and its value is insufficient to compensate for the decrease in the first term. The conclusion is that, in this process of give and take, because the contribution of the replaced dry air (i.e., the high-viscosity component) is far greater than the contribution of the newly added water vapor (i.e., the low-viscosity component), the overall... It shows a slight downward trend.

[0156] From the perspective of energy transfer in molecular dynamics, the viscosity of a gas is essentially the momentum exchange generated by the thermal motion of molecules. The molecular mass of dry air is much greater than that of water molecules. This means that during momentum transfer, heavier molecules transfer more momentum when colliding in laminar flow, resulting in greater internal friction (viscosity). Therefore, when humidity increases, lighter water molecules insert themselves between heavier dry air molecules. Although water molecules move at high speeds, their light mass results in less momentum transfer during collisions.

[0157] While increased humidity leads to a decrease in dynamic viscosity, the decrease is relatively slight. In contrast, temperature has a more significant effect on viscosity. (As temperature increases, the viscosity of gases increases significantly.)

[0158] 3) Kinematic viscosity ( ).

[0159] According to the definition of kinematic viscosity, we have:

[0160] (16)

[0161] In a gas mixture, the molecules change as humidity increases as follows:

[0162] 1. Water vapor molecules are more slippery than air molecules, resulting in a higher dynamic viscosity of the molecules. Slight decrease.

[0163] 2. According to the ideal gas density formula (6), under the same temperature and pressure, density is related to molecular weight. They are directly proportional. The average molecular weight of dry air is 28.97, while the molecular weight of water molecules is only 18.02. Therefore, the density of a gas mixture in a saturated state at 20°C typically decreases by about 1.2-1.5%. Thus, the kinematic viscosity of moist air (…) The kinematic viscosity of dry air is greater than that of dry air. ).

[0164] 4) Reynolds number ( ) calculation and mixing efficiency

[0165] Renosu is defined as:

[0166] (17)

[0167] Formula (17) : The flow rate generated by the fan; : is the characteristic length of the radon chamber.

[0168] Under constant fan speed, due to kinematic viscosity The Reynolds number increases with increasing humidity. A decrease in the Reynolds number means that the fluid shifts towards laminar or weakly turbulent flow. The reduced turbulence intensity directly weakens the entrainment and mixing capacity of radon atoms in the indoor airflow. In high humidity environments (RH > 60%), although the introduction of water vapor reduces air density, according to the Reynolds number formula... It was found that the disproportionate increase in kinematic viscosity led to The decrease indicates that the microturbulent diffusion within the radon chamber is suppressed, preventing the high concentration of radon near the radon source from rapidly and uniformly distributing to the sampling port of the measuring instrument, thus manifesting as a decrease in the measured concentration on a macroscopic scale.

[0169] The effect of humidity on changes in radon concentration is as follows:

[0170] Radon concentrations reached relatively high levels (up to 38.0 Bq / L) in the lower temperature range of 25-27°C and under moderate humidity (40%-50% RH); when the temperature rose above 29°C, radon concentrations showed a significant overall decreasing trend. Heat maps and contour maps showing the distribution of radon concentration with temperature and humidity were plotted. Figure 26 ).

[0171] Based on the data and the drawn contour heat map and line graph ( Figure 27 From this perspective, the radon concentration in the radon chamber exhibits a non-linear, dual-response characteristic as temperature and humidity change. Specifically:

[0172] 1) Temperature step effect. Radon concentration is relatively high between 25 and 27°C, peaking at 27°C / 40%RH (37.9 Bq / L). Between 29 and 35°C, radon concentration drops sharply, generally remaining between 16 and 23 Bq / L. This indicates a clear critical range between 27 and 29°C; as temperature increases, the radon concentration loss rate increases significantly, which may be related to radon permeation, leakage, or changes in adsorption characteristics within the radon chamber.

[0173] 2) The parabolic effect of humidity. At low temperatures (25 to 27°C), radon concentration initially increases and then decreases with temperature, reaching its peak at 40-50% RH. At high temperatures (29 to 35°C), the effect of humidity on concentration becomes more gradual, but a secondary decrease in concentration is generally observed in high humidity environments (80% RH).

[0174] Competitive adsorption of water molecules. At 30%-50% RH, a suitable amount of moisture may occupy the active adsorption sites on the inner wall of the radon chamber, reducing wall damage and increasing the gaseous concentration of radon. However, when the humidity exceeds 60%, a microscopic water film forms on the inner wall, and radon is easily soluble in water, leading to a decrease in concentration.

[0175] 1) Temperature-driven diffusion and penetration

[0176] Increased temperature enhances the thermal motion of radon molecules. According to the Clausius-Clapeyron equation, increased temperature favors the desorption of adsorbed radon, but may also enhance the permeability of the radon chamber sealing material or the diffusion rate through micro-cracks. The sharp drop in concentration after 29°C suggests that this temperature may have reached the glass transition point or the nonlinear growth point of the permeability coefficient of some sealing material. Increased temperature usually enhances the thermal motion of molecules, prompting radon gas deep within the pores to desorb more quickly and migrate to the surface. However, the low concentration observed after 29°C indicates that temperature is no longer the dominant factor, or that the release effect brought about by the temperature rise is offset by another inhibitory effect.

[0177] 2) The two-way effect of humidity

[0178] Regarding humidity, data analysis shows that radon concentration peaks typically occur around 40-50% RH, followed by a decline. The process can be divided into two stages: the first stage is low humidity, where moisture fills the tiny pores in the medium, creating a backwash effect and increasing radon precipitation. The second stage is high humidity, where the pores are filled with liquid water, forming a water film barrier. Since the diffusion coefficient of radon in water is much smaller than in air, high humidity significantly hinders radon migration. The effect of humidity on radon is generally bidirectional: at low humidity, water molecules occupy adsorption sites, facilitating radon desorption; however, at high humidity (such as 60%-80% RH in the experiment), pore water undergoes micropore condensation, forming a water film and even blocking diffusion channels. At 25°C-27°C, thermal motion is active and the water film has not yet reached the critical point of complete blockage; therefore, even small changes in humidity can significantly alter the resistance to molecular diffusion paths, exhibiting high sensitivity.

[0179] 3) Temperature and humidity coupling effect

[0180] The coupling effect of temperature and humidity is not a simple superposition, but a complex nonlinear interaction. For example, in the temperature range of 25-27℃, humidity fluctuations are highly sensitive to radon concentration; while above 29℃, the radon concentration in the radon chamber is low, and the regulatory effect of humidity tends to be milder. This coupling mechanism can perhaps be understood as follows: temperature determines the intensity of radon source release, while humidity determines the smoothness of the pathway. When the temperature is within a specific range, such as 29℃, it may trigger a dynamic equilibrium shift between the medium's moisture content and saturated vapor pressure, thus inhibiting the originally active diffusion process.

[0181] 4) Sensitivity drift

[0182] The high-concentration range is the sensitive zone, around 25°C, where the system is on the edge of equilibrium. Changing the humidity at this point is equivalent to changing a valve in a critical opening / closing state, hence the extremely high sensitivity. The low-concentration range is the passivation zone; after entering the 29°C-35°C range, due to the water seal effect or the medium's moisture content reaching near saturation, humidity's obstruction of the path has become "overloaded." At this point, regardless of humidity fluctuations, diffusion resistance remains high, causing the humidity regulation effect to tend to level off.

[0183] A significant inflection point occurs at 29°C. This may be related to the dynamic equilibrium shift of moisture on the medium surface. Around 29°C, moisture on the medium surface may transform from a "multilayer molecular adsorption state" to a "capillary condensation state." As the temperature crosses 29°C, under high saturated vapor pressure, the micropores on the medium surface may be rapidly filled with condensed water. Even if the temperature continues to rise and more radon is produced, the diffusion path is strongly blocked by the water seal effect (radon's diffusion coefficient in water is much lower than in air), ultimately leading to a plateau in the macroscopically observed concentration.

[0184] To investigate the physical mechanism of the 29℃ inflection point, a quantitative code analysis of the interaction effect was conducted using a Python model. The results are shown in Table 1.

[0185] Table 1. Dimensional decomposition and physical mechanism explanation of radon concentration variation trends.

[0186] Analysis Dimensions Experimental data observation and trend taking Core physical / chemical mechanisms Presentation Results Temperature-driven effect (25-27℃) Radon concentration was in the peak range (34.0-38.0 Bq / L). Thermal excitation and desorption: Increased temperature enhances the thermal kinetic energy of radon atoms, reducing the adsorption barrier on the medium surface. Within the medium and low temperature range, increased temperature significantly promotes the diffusion of radon from the source material into the air. Temperature inhibition effect (29-356℃) Radon concentration decreased significantly and fluctuated (15.6-23.5 Bq / L). Thermodynamic equilibrium shift: High temperature may cause changes in the micro-pressure difference in the room or thermal expansion of the microstructure of the medium, which alters the diffusion channels. High-temperature environments exhibit nonlinear suppression or complex interference effects on radon precipitation. Low humidity promoting effect (30-50%RH) Radon concentration increases with increasing humidity, reaching its peak at 40%-50%. Competitive adsorption mechanism: Water molecules are more polar than radon atoms and preferentially occupy active sites, "squeezing out" adsorbed radon into the gas phase. A moderate increase in humidity can produce a "displacement effect," increasing the concentration of free radon in the environment. High humidity shielding effect (60-80%RH) Radon concentration showed a significant downward trend. Capillary coagulation and pore blockage: Under high humidity, a water film forms in the micropores, and the diffusion rate of radon in water is much lower than that in air, thus obstructing its transport path. The physical barrier created by high humidity is the dominant factor in inhibiting radon diffusion. Temperature and humidity coupling interaction The contribution of humidity to radon concentration varies significantly at different temperatures. Synergistic / antagonistic effects: Temperature affects saturated vapor pressure, which in turn changes the state of moisture in the pores. Radon concentration changes are controlled by a second-order coupling of temperature and humidity, and there are obvious extreme points on the response surface.

[0187] To discuss the effects of two variables on radon concentration, a 3D surface projection diagram showing the influence of temperature gradient and humidity gradient on radon concentration in the radon chamber was drawn. Figure 28 The graph clearly shows: 1. Within the 25-35℃ range, the radon concentration in the radon chamber reaches its maximum between 25-27℃; subsequently, it decreases and then increases with rising temperature. 2. Within the 30-80% RH% humidity range, the radon concentration reaches its maximum at low humidity, then decreases and then increases with increasing humidity. 3. From the overall surface plot, the change in radon concentration does not exhibit a monotonic change with temperature or humidity, but rather a non-monotonic change.

[0188] Generally, increased temperature increases the diffusion rate of radon gas. For example, when studying the radon release rate in uranium tailings ponds, the effect of temperature must be considered. Increased temperature increases the diffusion rate of radon in uranium tailings, causing more radon gas to be released from the ore into the atmosphere. Furthermore, temperature fluctuations also affect radon release. The formula for calculating the radon release rate is:

[0189] (18)

[0190] In formula (18), Radon release rate, Bq·m -2 ·s -1 ; Radon concentration at time t, Bq / m 3 ; Initial radon concentration, Bq / m³ 3 ; Area of ​​the measured region, in meters (m²) 2 ; : Height of the gas collection hood, in meters (m).

[0191] Formula (18) indicates that the factors affecting the radon release rate within the gas collection hood are changes in radon concentration, the area of ​​the measured region, and the height of the gas collection hood. In fact, as mentioned in the text, temperature fluctuations affect radon release; humidity also affects radon migration. However, the formula here cannot reflect the influence of factors such as temperature and humidity on radon migration.

[0192] Furthermore, according to the tailings radon diffusion and migration equation:

[0193] (19)

[0194] In formula (19), Radon concentration in tailings, Bq / m³ 3 ; : The diffusion coefficient of radon in a specific medium, m 2 / s; Fluid velocity, m / s; The decay constant of radon, s -1 ; The ability of radium-containing ore in tailings to generate radon, Bq / (m 3 ·s); Time, seconds.

[0195] The diffusion coefficient is a crucial factor to consider in the diffusion and migration of radon, and it is influenced by various factors such as temperature and humidity. Temperature also affects pressure changes, which in turn affect convection velocity. Increased temperature increases the diffusion coefficient and porosity of radon, thus accelerating its migration and release. Changes in humidity affect the porosity and gas permeability in tailings, indirectly influencing radon migration.

[0196] Furthermore, a method was proposed to quantitatively analyze the impact of meteorological parameters on radon release rate by calculating the Kolmogorov entropy of the product of radon release rate time series and temperature, air pressure, and humidity. The specific formula is as follows:

[0197] (20)

[0198] In formula (20), Power density spectrum; Data points.

[0199] In addition, studies on radon gas evolution from uranium tailings have pointed out the influence of temperature changes on the radon diffusion coefficient, with the specific formula as follows:

[0200] (twenty one)

[0201] In formula (21), : Effective diffusion coefficient of radon, m 2 / s; The decay constant of radon; Cover thickness, in meters; Radon release rate from tailings surface before backfilling, Bq / m 2 ·s; Radon release rate from tailings surface after backfilling, Bq / m 2 ·s.

[0202] Formula (21) shows the influence of soil thickness and radon diffusion coefficient on radon release rate. Soil thickness affects temperature change, and temperature and humidity affect diffusion coefficient. However, a model of the direct influence of temperature and humidity on radon transport is lacking.

[0203] In view of this, based on the surface Figure 28 The U-shaped characteristics are presented. A quadratic polynomial model is adopted for the measured data, using equation (1). The process will not be repeated here. The final model expression is:

[0204] (twenty two)

[0205] The coefficient of determination of formula (22) is R. 2 =0.914, indicating a good fit.

[0206] Furthermore, radon concentration often reaches a turning point, or threshold, when humidity exceeds 50%. Now, based on the derived model, we will calculate the cases for humidity levels below 50% and above 50%. Taking the derivative with respect to humidity, we have: (twenty three)

[0207] With H=30% and T=30℃, the radon concentration increases by 0.36 Bq / L for every 1% increase in humidity. When the humidity exceeds 50%, a supersaturated water film becomes involved, which inhibits radon diffusion, resulting in a negative derivative.

[0208] Differentiating equation (23) with respect to temperature, we have:

[0209] (24) (4-23)

[0210] Setting equation (24) to zero, we obtain the critical temperature:

[0211] (25)

[0212] When H=30%, ℃, which clarifies that all the data indicate that radon concentration increases from 25 to 27℃, and that further heating promotes radon release; when H=70%, At ℃, heating will inhibit the release of radon across the entire temperature range.

[0213] like Figure 29 This indicates that the effect of temperature and humidity on radon concentration is not monotonic. Therefore, using Equation 4-12 and substituting the data into the matrix using Python, we have:

[0214] (26)

[0215] The coefficient of determination of formula (26) is R. 2=0.87, indicating that the fit is acceptable.

[0216] According to formula (26), the linear term ( This indicates that an initial increase in humidity promotes radon release; the quadratic term ( This indicates that excessive humidity inhibits radon diffusion; the linear term ( This indicates that increased temperature accelerates the volatilization of radon; the quadratic term ( This indicates that high temperatures may trigger convection or pressure changes, inhibiting local accumulation; the interaction term ( This indicates that under high temperature and high humidity conditions, the synergistic effect reduces radon concentration.

[0217] Furthermore, by taking the partial derivatives of equation (26) with respect to temperature and humidity, we can obtain the temperature and humidity at which the radon concentration is at its maximum:

[0218] (27)

[0219] (28)

[0220] Solving for H, we find that the radon concentration is highest at approximately 45% and T approximately 28℃. For example, in a relatively enclosed environment, controlling the humidity at 30-50% and the temperature below 25℃ can effectively reduce the radon concentration.

[0221] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A method for synergistically regulating radon concentration in a radon chamber using temperature and humidity, characterized in that, include: S1. Radon gas from the groundwater is extracted and injected into the radon chamber through a bubbling degassing device to establish a non-radium source steady-state radon chamber system; S2. In the non-radium source steady-state radon chamber system, the internal temperature of the radon chamber is kept constant, and the relative humidity is adjusted by gradient through humidification or dehumidification equipment to explore the inhibitory effect of water molecule competitive adsorption on the radon surface release rate and the gas diffusion viscosity resistance mechanism, and to obtain data on the change of radon concentration with humidity. S3. Based on the data on the change of radon concentration with humidity, determine the critical humidity threshold when the radon concentration reaches its peak, wherein the critical humidity threshold is 40%-50%RH; S4. In the non-radium source steady-state radon chamber system, the relative humidity inside the radon chamber is kept constant, and the temperature is adjusted stepwise by a temperature control device to analyze the nonlinear relationship between the temperature-dependent Henry coefficient and the radon concentration change. S5. Based on the determined critical humidity threshold and the analyzed temperature dependence, construct a quadratic regression model to describe the radon concentration change law under the combined effect of temperature and humidity, and calculate the optimal temperature and humidity combination corresponding to the extreme point of radon concentration based on the quadratic regression model.

2. The method for synergistic temperature and humidity control of radon concentration in a radon chamber according to claim 1, characterized in that, In S2, the process of gradient adjustment of relative humidity includes maintaining the relative humidity in the radon chamber at 30%RH, 40%RH, 50%RH, 60%RH, 70%RH and 80%RH respectively, and measuring the change of radon concentration in the radon chamber at each humidity level.

3. The method for synergistic temperature and humidity control of radon concentration in a radon chamber according to claim 1, characterized in that, In S4, the stepwise temperature control process includes adjusting the temperature in the radon chamber to 25°C, 27°C, 29°C, 31°C, 33°C and 35°C respectively, and measuring the change in radon concentration in the radon chamber at each temperature level.

4. The method for synergistic temperature and humidity control of radon concentration in a radon chamber according to claim 1, characterized in that, In S5, the expression for the quadratic regression model is: Where C represents radon concentration, T represents temperature, and H represents relative humidity. to is the regression coefficient.

5. The method for synergistic temperature and humidity control of radon concentration in a radon chamber according to claim 1, characterized in that, In S5, when the relative humidity is below 50%RH, the radon concentration increases with increasing temperature; when the relative humidity is above 60%RH, the radon concentration decreases with increasing temperature.

6. The method for synergistic temperature and humidity control of radon concentration in a radon chamber according to claim 1, characterized in that, In S5, the process of calculating the optimal temperature and humidity combination corresponding to the extreme point of radon concentration includes: taking the partial derivatives of the quadratic regression model with respect to temperature and humidity respectively, setting the partial derivatives to zero, and solving for the temperature at which the radon concentration is maximum to be 28℃ and the relative humidity to be 45%.

7. A system for implementing the method of temperature and humidity coordinated regulation of radon concentration in a radon chamber as described in any one of claims 1-6, characterized in that, include: The radon gas generating module is configured to extract radon gas from groundwater through a bubbling degassing device and inject it into the radon chamber to establish a non-radium source steady-state radon chamber system. The environmental control module is configured to perform constant temperature and humidity control and constant humidity and temperature control operations respectively in the non-radium source steady-state radon chamber system, wherein the constant temperature and humidity control is used to gradient adjust the relative humidity, and the constant humidity and temperature control is used to stepwise adjust the temperature. The data acquisition module is configured to monitor and record radon concentration, temperature, and humidity data in the radon chamber in real time. The data processing module is configured to build a quadratic regression model based on the collected data and calculate the optimal temperature and humidity combination corresponding to the extreme point of radon concentration. The control feedback module is configured to adjust the operating parameters of the environmental control module according to the optimal temperature and humidity combination, so as to achieve coordinated control of radon concentration.

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